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nix-thunk (empty) → 0.7.2.2

raw patch · 9 files changed

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+ CHANGELOG.md view
@@ -0,0 +1,78 @@+# Revision history for nix-thunk++## 0.7.2.2++* Support GHC 9.12++## 0.7.2.1+* Loosen version bounds+* Fix issue where thunk branches aren't updated when the user specifies --branch on nix-thunk update+* Swap default.nix and lib.nix++## 0.7.2.0+* Support retrieving revs that aren't on the default branch when a branch isn't specified.  To use this functionality, update your thunks.++## 0.7.1.0+* Allow specifying `--rev` when doing `update` to update to a specific revision.++## 0.7.0.1++* Support GHC 9.6++## 0.7.0.0++* Caching now works+* [#42](https://github.com/obsidiansystems/nix-thunk/pull/42) Thunk read errors are now presented in a more informative manner.+* [#43](https://github.com/obsidiansystems/nix-thunk/pull/43) `nix-thunk` will now ensure that any `git` processes invoked during its execution have a clean configuration.+  This prevents `nix-thunk` crashing when e.g. the user's configuration `git` is valid only in a version newer than what `nix-thunk` links against, and works towards making thunks more reproducible by ensuring that thunk URIs are resolvable independently of the user's environment.++## 0.6.1.0++* [#36](https://github.com/obsidiansystems/nix-thunk/pull/36) Expose the internals of the `nix-thunk` library.++## 0.6.0.0++* [#34](https://github.com/obsidiansystems/nix-thunk/pull/34) Fix an+  issue where thunks could not be fetched without `nix-thunk` (or one of+  its dependents, e.g. `obelisk`) being installed. Please update all+  your thunks to use the new v8 thunk spec.++  Updating your thunk can be done by running `nix-thunk unpack $path; nix-thunk pack $path`.++* [#35](https://github.com/obsidiansystems/nix-thunk/pull/35) Determine remote using git-config when `branch.<name>.merge` option is set+  (Fixes [obelisk#792](https://github.com/obsidiansystems/obelisk/issues/792).)++## 0.5.1.0++* Bump to cli-nix 0.2.0.0; This ensures that `nix-prefetch-git` can always be found.++## 0.5.0.0++* Fix a critical bug where v6 thunks can not be used to fetch non-GitHub repositories. Please update all your thunks to use the new v7 thunk spec.+  Updating your thunk can be done by running `nix-thunk unpack $path; nix-thunk pack $path`.+* Building a functional `nix-thunk` _must_ be done using the included Nix derivation.++## 0.4.0.0++* The default thunk specification ("v6") now uses a pinned version of nixpkgs, rather than the magic `<nixpkgs>`, for fetching thunks. This ensures that thunks can be fetched even in an environment where `NIX_PATH` is unset.++## 0.3.0.0++* Fix readThunk when thunk is checked out [#4](https://github.com/obsidiansystems/nix-thunk/pull/4)+* Fix removal of .git from default destination [#10](https://github.com/obsidiansystems/nix-thunk/pull/10)++## 0.2.0.3++* Default to GHC 8.8.4 and update dependency bounds++## 0.2.0.2+* Add support for GHC 8.8.4.++## 0.2.0.1+* Fix parsing of --rev arguments++## 0.2.0.0+* Add nix-thunk create.  This caused some minor breakage to the Haskell library API, but not the Nix or command line interfaces.++## 0.1.0.0+* Initial release.  Extracted the Nix part of this code from https://github.com/obsidiansystems/reflex-platform and the Haskell part from https://github.com/obsidiansystems/obelisk
+ LICENSE view
@@ -0,0 +1,30 @@+Copyright (c) 2020 Obsidian Systems LLC++All rights reserved.++Redistribution and use in source and binary forms, with or without+modification, are permitted provided that the following conditions are met:++    * Redistributions of source code must retain the above copyright+      notice, this list of conditions and the following disclaimer.++    * Redistributions in binary form must reproduce the above+      copyright notice, this list of conditions and the following+      disclaimer in the documentation and/or other materials provided+      with the distribution.++    * Neither the name of Obsidian Systems LLC nor the names of other+      contributors may be used to endorse or promote products derived+      from this software without specific prior written permission.++THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ README.md view
@@ -0,0 +1,112 @@+nix-thunk+=========+[![Haskell](https://img.shields.io/badge/language-Haskell-orange.svg)](https://haskell.org) [![Hackage](https://img.shields.io/hackage/v/nix-thunk.svg)](https://hackage.haskell.org/package/nix-thunk) [![Github CI](https://github.com/obsidiansystems/nix-thunk/workflows/github-action/badge.svg)](https://github.com/obsidiansystems/nix-thunk/actions) [![BSD3 License](https://img.shields.io/badge/license-BSD3-blue.svg)](https://github.com/obsidiansystems/nix-thunk/blob/master/LICENSE)++nix-thunk is a lightweight Nix dependency manager, focused on making it easy to contribute improvements back to libraries you depend on.++nix-thunk does this by creating and managing "thunks" - directories that stand in for full git repositories.+Like git submodules, they pin a specific commit of the target repository, but unlike git submodules, you don't have to clone them to use them.+nix-thunk makes them "transparent" to Nix scripts, so any script that calls `import path/to/some/thunk` will work the same on the thunk as it does on the original repository.++* [Installation](#installation)+* [Command Usage](#command-usage)+  * [Create a dependency](#create-a-dependency)+  * [Work on a dependency](#work-on-a-dependency)+  * [Update a dependency](#update-a-dependency)+* [Nix Usage](#nix-usage)+* [Contributing](#contributing)+* [License](#license)++## Installation++```bash+nix-env -f https://github.com/obsidiansystems/nix-thunk/archive/master.tar.gz -iA command+```++**WARNING**: It is _not_ possible to compile `nix-thunk` without Nix.+To ensure that packed thunks are buildable even in environments where diamond paths are unavailable (specifically `<nixpkgs>`), `nix-thunk` _must_ be built with knowledge of a known-good nixpkgs, _and_ for `nix-thunk` to be able to manipulate these thunks, it must _always_ be the same version of nixpkgs.++## Command Usage++### Create a dependency++```bash+nix-thunk create https://example.com/some-dep+```++If you have already cloned the dependency as a git repository, you can just `pack` it instead:++```bash+nix-thunk pack some-dep+```++### Work on a dependency++If you discover a bug fix or improvement that your dependency needs, you can use `nix-thunk unpack path/to/your/dependency` to turn the thunk back into a full checkout of the repository.+Your Nix scripts should continue working, and you can modify the dependency's source code, push it to a branch or a fork, send a pull request, and then use `nix-thunk pack path/to/your/dependency` to pack it back up into a thunk.+When the dependency accepts your pull request, you can easily update the thunk.++```bash+nix-thunk unpack some-dep+# Improve some-dep and push your work to a branch+nix-thunk pack some-dep+```++### Update a dependency++For routine updates, you can run `nix-thunk update path/to/your/dependency` to point the thunk at the latest version of the dependency without needing to do a `nix-thunk unpack` or a `git clone`.++```bash+nix-thunk update some-dep+```++## Nix Usage++The [`default.nix`](default.nix) file in this repository defines the nix function, `thunkSource`.+This can be used in your nix files to access the contents of thunks.+In the following example, a thunk is used in place of the source location argument to `callCabal2nix`.+`thunkSource` works whether the thunk is packed or unpacked, making it convenient to run nix commands with modified thunks.++```nix+  haskellPackages = pkgs.haskell.packages.ghc865.override {+    overrides = self: super: {+      which = self.callCabal2nix "which" (thunkSource ./dep/which) {};+    };+  };+```++You can also represent in nix all the thunks of a given directory+```nix+let sources = nix-thunk.mapSubdirectories nix-thunk.thunkSource ./dep;+```+```nix+{ which = self.callCabal2nix "which" sources.which {}; }+```++You can also access subfolders of a thunk.+For example:++```nix+{+  imports = [ "${builtins.fetchTarball <some-tar-url>}/path/to/subfolder" ];+}+```+becomes+```+{+  imports = [ "${nix-thunk.thunkSource <thunk-location>}/path/to/subfolder>" ];+}+```++## Contributing++Pull requests are welcome.+For major changes, please open an issue first to discuss what you would like to change.+See the [contribution guide](CONTRIBUTING.md) for more details.++## License+[BSD3](./LICENSE)++***++![Obsidian Systems](https://obsidian.systems/static/images/ObsidianSystemsLogo.svg)
+ Setup.hs view
@@ -0,0 +1,2 @@+import Distribution.Simple+main = defaultMain
+ nix-thunk.cabal view
@@ -0,0 +1,78 @@+cabal-version:      >=1.10+name:               nix-thunk+version:            0.7.2.2+license:            BSD3+license-file:       LICENSE+copyright:          Obsidian Systems LLC 2020-2022+maintainer:         maintainer@obsidian.systems+author:             Obsidian Systems LLC+bug-reports:        https://github.com/obsidiansystems/nix-thunk+synopsis:           Lightweight dependency management with Nix+description:+  nix-thunk lets you manage source code dependencies in a lightweight and reproducible way, using Nix.  Each source repository is represented by a stub directory, which refers to the original Git repository.  nix-thunk can easily update these dependencies.+  .+  If you need to make improvements to the original repositories, nix-thunk can unpack them in-place, so that changes can be tested right away, and then pack them back up when you're done.  This makes it easy to send a pull request to the upstream repo while your project continues on a fork, then switch back to upstream once your pull request has been merged.++category:           Nix, Git+build-type:         Simple+extra-source-files:+  CHANGELOG.md+  README.md++tested-with: GHC ==8.6.5 || ==8.8.4 || ==8.10.7 || ==9.0.1 || ==9.2.5 || ==9.4.5 || ==9.6.1 || ==9.8.2 || ==9.10.1 || ==9.12.2++library+  exposed-modules:+    Nix.Thunk+    Nix.Thunk.Internal+    Nix.Thunk.Command++  hs-source-dirs:   src+  default-language: Haskell2010+  ghc-options:      -Wall+  build-depends:+      aeson                 >=1.4.4.0  && <2.3+    , aeson-pretty          >=0.8.7    && <0.9+    , base                  >=4.12.0.0 && <4.22+    , bytestring            >=0.10.8.2 && <0.13+    , cli-extras            >=0.2.1.0  && <0.3+    , cli-git               >=0.2.0.0  && <0.3+    , cli-nix               >=0.2.0.0  && <0.3+    , containers            >=0.6.0.1  && <0.8+    , cryptonite            >=0.25     && <0.31+    , data-default          >=0.7.1.1  && <0.9+    , directory             >=1.3.3.0  && <1.4+    , either                >=5.0.1.1  && <5.1+    , exceptions            >=0.10.3   && <0.11+    , extra                 >=1.6.18   && <1.9+    , filepath              >=1.4.2.1  && <1.6+    , github                >=0.25     && <0.31+    , here                  >=1.2.13   && <1.3+    , lens                  >=4.17.1   && <5.4+    , logging-effect        >=1.3.4    && <1.5+    , megaparsec            >=7.0.5    && <9.8+    , memory                >=0.14     && <0.19+    , modern-uri            >=0.3.1.0  && <0.4+    , monad-logger          >=0.3.30   && <0.4+    , mtl                   >=2.2.2    && <2.4+    , optparse-applicative  >=0.14.3.0 && <0.20+    , temporary             >=1.3      && <1.4+    , text                  >=1.2.3.1  && <2.2+    , time                  >=1.8.0.2  && <1.15+    , unix                  >=2.7.2.2  && <2.9+    , which                 >=0.2      && <0.3+    , yaml                  >=0.11.1.2 && <0.12++executable nix-thunk+  main-is:          src-bin/nix-thunk.hs+  default-language: Haskell2010+  build-depends:+      base+    , cli-extras+    , nix-thunk+    , optparse-applicative+    , text++source-repository head+  type:     git+  location: git://github.com/obsidiansystems/nix-thunk.git
+ src-bin/nix-thunk.hs view
@@ -0,0 +1,59 @@+import Nix.Thunk+import Nix.Thunk.Command+import Options.Applicative+import Cli.Extras+import qualified Data.Text.IO as T+import System.Environment+import System.Exit+import System.IO+import Data.List+import Data.Void++data Args = Args+  { _args_verbose :: Bool+  , _args_command :: ThunkCommand+  }++verbose :: Parser Bool+verbose = flag False True $ mconcat+  [ long "verbose"+  , short 'v'+  , help "Produce more detailed output"+  ]++args :: Parser Args+args = Args <$> verbose <*> thunkCommand++argsInfo :: ParserInfo Args+argsInfo = info (args <**> helper) $ mconcat+  [ fullDesc+  , progDesc "Manage source repositories using Nix"+  ]++parserPrefs :: ParserPrefs+parserPrefs = defaultPrefs+  { prefShowHelpOnEmpty = True+  }++main :: IO ()+main =+  do+    args <- getArgs+    args' <- handleParseResult $ execParserPure parserPrefs argsInfo args+    let logLevel = if _args_verbose args' then Debug else Notice+    notInteractive <- not <$> isInteractiveTerm args+    cliConf <- newCliConfig logLevel notInteractive notInteractive (\e -> (prettyNixThunkError e, ExitFailure 1))+    runCli cliConf (runThunkCommand (_args_command args'))+  where+    isInteractiveTerm args = do+      isTerm <- hIsTerminalDevice stdout+      -- Running in bash/fish/zsh completion+      let inShellCompletion = isInfixOf "completion" $ unwords args++      -- Respect the user’s TERM environment variable. Dumb terminals+      -- like Eshell cannot handle lots of control sequences that the+      -- spinner uses.+      termEnv <- lookupEnv "TERM"+      let isDumb = termEnv == Just "dumb"++      return $ isTerm && not inShellCompletion && not isDumb
+ src/Nix/Thunk.hs view
@@ -0,0 +1,39 @@+module Nix.Thunk+  ( ThunkSource (..)+  , GitHubSource (..)+  , ThunkRev (..)+  , getLatestRev+  , gitCloneForThunkUnpack+  , thunkSourceToGitSource+  , ThunkPtr (..)+  , ThunkData (..)+  , readThunk+  , CheckClean (..)+  , getThunkPtr+  , packThunk+  , createThunk+  , createThunk'+  , createWorktree+  , CreateWorktreeConfig (..)+  , ThunkPackConfig (..)+  , ThunkConfig (..)+  , updateThunkToLatest+  , updateThunk+  , ThunkUpdateConfig (..)+  , unpackThunk+  , ThunkSpec (..)+  , ThunkFileSpec (..)+  , NixThunkError+  , nixBuildAttrWithCache+  , attrCacheFileName+  , prettyNixThunkError+  , ThunkCreateSource (..)+  , ThunkCreateConfig (..)+  , parseGitUri+  , GitUri (..)+  , uriThunkPtr+  , Ref(..)+  , refFromHexString+  ) where++import Nix.Thunk.Internal
+ src/Nix/Thunk/Command.hs view
@@ -0,0 +1,97 @@+{-# LANGUAGE FlexibleContexts #-}+{-# LANGUAGE LambdaCase #-}+module Nix.Thunk.Command where++import Cli.Extras (HasCliConfig, Output)+import Control.Monad.Catch (MonadMask)+import Control.Monad.Error.Class (MonadError)+import Control.Monad.Fail (MonadFail)+import Control.Monad.IO.Class (MonadIO)+import Control.Monad.Log (MonadLog)+import Data.List.NonEmpty (NonEmpty(..))+import qualified Data.Text as T+import Options.Applicative+import System.FilePath++import Nix.Thunk++thunkConfig :: Parser ThunkConfig+thunkConfig = ThunkConfig+  <$>+    (   flag' (Just True) (long "private" <> help "Mark thunks as pointing to a private repository")+    <|> flag' (Just False) (long "public" <> help "Mark thunks as pointing to a public repository")+    <|> pure Nothing+    )++thunkUpdateConfig :: Parser ThunkUpdateConfig+thunkUpdateConfig = ThunkUpdateConfig+  <$> optional (strOption (short 'b' <> long "branch" <> metavar "BRANCH" <> help "Use the given branch when looking for the latest revision"))+  <*> optional (strOption (short 'r' <> long "rev" <> metavar "REVISION" <> help "Update to this specific revision"))+  <*> thunkConfig++thunkPackConfig :: Parser ThunkPackConfig+thunkPackConfig = ThunkPackConfig+  <$> switch (long "force" <> short 'f' <> help "Force packing thunks even if there are branches not pushed upstream, uncommitted changes, stashes. This will cause changes that have not been pushed upstream to be lost; use with care.")+  <*> thunkConfig++thunkCreateConfig :: Parser ThunkCreateConfig+thunkCreateConfig = ThunkCreateConfig+  <$> argument source (metavar "URI" <> help "Address of the target repository")+  <*> optional (strOption (short 'b' <> long "branch" <> metavar "BRANCH" <> help "Point the new thunk at the given branch"))+  <*> optional (option (refFromHexString <$> str) (long "rev" <> long "revision" <> metavar "REVISION" <> help "Point the new thunk at the given revision"))+  <*> thunkConfig+  <*> optional (strArgument (action "directory" <> metavar "DESTINATION" <> help "The name of a new directory to create for the thunk"))+  where+    source = (ThunkCreateSource_Absolute <$> maybeReader (parseGitUri . T.pack))+         <|> (ThunkCreateSource_Relative <$> str)++createWorktreeConfig :: Parser CreateWorktreeConfig+createWorktreeConfig = CreateWorktreeConfig+  <$> optional (strOption (short 'b' <> long "branch" <> metavar "BRANCH" <> help "create a new branch"))+  <*> switch (long "detach" <> short 'd' <> help "detach HEAD at the commit specified in thunk")++data ThunkCommand+  = ThunkCommand_Update ThunkUpdateConfig (NonEmpty FilePath)+  | ThunkCommand_Unpack (NonEmpty FilePath)+  | ThunkCommand_Worktree CreateWorktreeConfig (FilePath, FilePath)+  | ThunkCommand_Pack ThunkPackConfig (NonEmpty FilePath)+  | ThunkCommand_Create ThunkCreateConfig+  deriving Show++thunkDirList :: Parser (NonEmpty FilePath)+thunkDirList = (:|)+  <$> dirArg (metavar "THUNKDIRS..." <> help "Paths to directories containing thunk data")+  <*> many (dirArg mempty)++createWorktreeArgs :: Parser (FilePath, FilePath)+createWorktreeArgs = (,)+  <$> dirArg (metavar "THUNKDIR" <> help "Path to directory containing thunk data")+  <*> dirArg (metavar "GITDIR" <> help "Path to local git repo")++dirArg :: Mod ArgumentFields FilePath -> Parser FilePath+dirArg opts = fmap (dropTrailingPathSeparator . normalise) $ strArgument $ action "directory" <> opts++thunkCommand :: Parser ThunkCommand+thunkCommand = hsubparser $ mconcat+  [ command "update" $ info (ThunkCommand_Update <$> thunkUpdateConfig <*> thunkDirList) $ progDesc "Update packed thunk to latest revision available on the tracked branch"+  , command "unpack" $ info (ThunkCommand_Unpack <$> thunkDirList) $ progDesc "Unpack thunk into git checkout of revision it points to"+  , command "worktree" $ info (ThunkCommand_Worktree <$> createWorktreeConfig <*> createWorktreeArgs) $ progDesc "Create a git worktree of the thunk using the specified local git repo"+  , command "pack" $ info (ThunkCommand_Pack <$> thunkPackConfig <*> thunkDirList) $ progDesc "Pack git checkout or unpacked thunk into thunk that points at the current branch's upstream"+  , command "create" $ info (ThunkCommand_Create <$> thunkCreateConfig) $ progDesc "Create a packed thunk without cloning the repository first"+  ]++runThunkCommand+  :: ( MonadLog Output m+     , HasCliConfig NixThunkError m+     , MonadIO m+     , MonadMask m+     , MonadError NixThunkError m+     , MonadFail m+     )+  => ThunkCommand -> m ()+runThunkCommand = \case+  ThunkCommand_Update config dirs -> mapM_ (updateThunkToLatest config) dirs+  ThunkCommand_Unpack dirs -> mapM_ unpackThunk dirs+  ThunkCommand_Worktree config (thunkDir, gitDir) -> createWorktree thunkDir gitDir config+  ThunkCommand_Pack config dirs -> mapM_ (packThunk config) dirs+  ThunkCommand_Create config -> createThunk' config
+ src/Nix/Thunk/Internal.hs view
@@ -0,0 +1,1686 @@+{-# LANGUAGE ConstraintKinds #-}+{-# LANGUAGE DataKinds #-}+{-# LANGUAGE DeriveDataTypeable #-}+{-# LANGUAGE FlexibleContexts #-}+{-# LANGUAGE GeneralizedNewtypeDeriving #-}+{-# LANGUAGE LambdaCase #-}+{-# LANGUAGE MultiParamTypeClasses #-}+{-# LANGUAGE MultiWayIf #-}+{-# LANGUAGE OverloadedStrings #-}+{-# LANGUAGE PatternGuards #-}+{-# LANGUAGE QuasiQuotes #-}+{-# LANGUAGE ScopedTypeVariables #-}+{-# LANGUAGE TemplateHaskell #-}+{-# LANGUAGE TupleSections #-}+{-# LANGUAGE TypeApplications #-}+module Nix.Thunk.Internal where++import Bindings.Cli.Coreutils (cp)+import Bindings.Cli.Git+    ( ensureCleanGitRepo,+      gitLookupCommitForRef,+      gitLookupDefaultBranch,+      gitLsRemote,+      gitProc,+      gitProcNoRepo,+      isolateGitProc,+      CommitId,+      GitRef(GitRef_Branch) )+import Bindings.Cli.Nix+import Cli.Extras+import Control.Applicative+import Control.Exception (Exception, displayException, throw, try)+import Control.Lens ((.~), ifor, ifor_, makePrisms)+import Control.Monad+import Control.Monad.Catch (MonadCatch, MonadMask, handle)+import Control.Monad.Except+import Control.Monad.Extra (findM)+import Control.Monad.Fail (MonadFail)+import Control.Monad.IO.Class (MonadIO(liftIO))+import Control.Monad.Log (MonadLog)+import Crypto.Hash (Digest, HashAlgorithm, SHA1, digestFromByteString)+import Data.Aeson ((.=))+import qualified Data.Aeson as Aeson+import Data.Aeson.Encode.Pretty+import qualified Data.Aeson.Types as Aeson+import Data.Bifunctor (first)+import Data.ByteArray.Encoding (Base(..), convertFromBase, convertToBase)+import Data.ByteString (ByteString)+import qualified Data.ByteString.Char8 as BSC+import qualified Data.ByteString.Lazy as LBS+import Data.Containers.ListUtils (nubOrd)+import Data.Data (Data)+import Data.Default+import Data.Either.Combinators (fromRight', rightToMaybe)+import Data.Foldable (for_, toList)+import Data.Function+import qualified Data.List as L+import Data.List.NonEmpty (NonEmpty(..), nonEmpty)+import qualified Data.List.NonEmpty as NonEmpty+import Data.Map (Map)+import qualified Data.Map as Map+import Data.Maybe+import Data.Set (Set)+import qualified Data.Set as Set+import Data.String.Here.Interpolated (i)+import Data.String.Here.Uninterpolated (here)+import Data.Text (Text)+import qualified Data.Text as T+import Data.Text.Encoding+import qualified Data.Text.IO as T+import Data.Time.Clock.POSIX (posixSecondsToUTCTime)+import Data.Traversable+import Data.Typeable (Typeable)+import Data.Yaml (parseMaybe)+import GitHub+import GitHub.Data.Name+import System.Directory+import System.Exit+import System.FilePath+import System.IO.Error (isDoesNotExistError)+import System.IO.Temp+import System.Posix.Files+import qualified Text.URI as URI++--------------------------------------------------------------------------------+-- Hacks+--------------------------------------------------------------------------------++type MonadInfallibleNixThunk m =+  ( CliLog m+  , HasCliConfig NixThunkError m+  , MonadIO m+  , MonadMask m+  )++type MonadNixThunk m =+  ( MonadInfallibleNixThunk m+  , CliThrow NixThunkError m+  , MonadFail m+  )++data NixThunkError+   = NixThunkError_ProcessFailure ProcessFailure+   | NixThunkError_Unstructured Text++prettyNixThunkError :: NixThunkError -> Text+prettyNixThunkError = \case+  NixThunkError_ProcessFailure (ProcessFailure p code) ->+    "Process exited with code " <> T.pack (show code) <> "; " <> reconstructCommand p+  NixThunkError_Unstructured msg -> msg++makePrisms ''NixThunkError++instance AsUnstructuredError NixThunkError where+  asUnstructuredError = _NixThunkError_Unstructured++instance AsProcessFailure NixThunkError where+  asProcessFailure = _NixThunkError_ProcessFailure++--------------------------------------------------------------------------------+-- End hacks+--------------------------------------------------------------------------------++--TODO: Support symlinked thunk data+data ThunkData+   = ThunkData_Packed ThunkSpec ThunkPtr+   -- ^ Packed thunk+   | ThunkData_Checkout+   -- ^ Checked out thunk that was unpacked from this pointer++-- | A reference to the exact data that a thunk should translate into+data ThunkPtr = ThunkPtr+  { _thunkPtr_rev :: ThunkRev+  , _thunkPtr_source :: ThunkSource+  }+  deriving (Show, Eq, Ord)++type NixSha256 = Text --TODO: Use a smart constructor and make this actually verify itself++-- | A specific revision of data; it may be available from multiple sources+data ThunkRev = ThunkRev+  { _thunkRev_commit :: Ref SHA1+  , _thunkRev_nixSha256 :: NixSha256+  }+  deriving (Show, Eq, Ord)++-- | A location from which a thunk's data can be retrieved+data ThunkSource+   -- | A source specialized for GitHub+   = ThunkSource_GitHub GitHubSource+   -- | A plain repo source+   | ThunkSource_Git GitSource+   deriving (Show, Eq, Ord)++thunkSourceToGitSource :: ThunkSource -> GitSource+thunkSourceToGitSource = \case+  ThunkSource_GitHub s -> forgetGithub False s+  ThunkSource_Git s -> s++setThunkSourceBranch :: Maybe (Name Branch) -> ThunkSource -> ThunkSource+setThunkSourceBranch mb = \case+  ThunkSource_GitHub s -> ThunkSource_GitHub $ s { _gitHubSource_branch = mb }+  ThunkSource_Git s -> ThunkSource_Git $ s { _gitSource_branch = mb }++data GitHubSource = GitHubSource+  { _gitHubSource_owner :: Name Owner+  , _gitHubSource_repo :: Name Repo+  , _gitHubSource_branch :: Maybe (Name Branch)+  , _gitHubSource_private :: Bool+  }+  deriving (Show, Eq, Ord)++newtype GitUri = GitUri { unGitUri :: URI.URI } deriving (Eq, Ord, Show)++gitUriToText :: GitUri -> Text+gitUriToText (GitUri uri)+  | (T.toLower . URI.unRText <$> URI.uriScheme uri) == Just "file"+  , Just (_, path) <- URI.uriPath uri+  = "/" <> T.intercalate "/" (map URI.unRText $ NonEmpty.toList path)+  | otherwise = URI.render uri++data GitSource = GitSource+  { _gitSource_url :: GitUri+  , _gitSource_branch :: Maybe (Name Branch)+  , _gitSource_fetchSubmodules :: Bool+  , _gitSource_private :: Bool+  }+  deriving (Show, Eq, Ord)++newtype ThunkConfig = ThunkConfig+  { _thunkConfig_private :: Maybe Bool+  } deriving Show++data ThunkUpdateConfig = ThunkUpdateConfig+  { _thunkUpdateConfig_branch :: Maybe Text+  , _thunkUpdateConfig_ref :: Maybe Text+  , _thunkUpdateConfig_thunk :: ThunkConfig+  } deriving Show++data ThunkPackConfig = ThunkPackConfig+  { _thunkPackConfig_force :: Bool+  , _thunkPackConfig_config :: ThunkConfig+  } deriving Show++-- | The source to be used for creating thunks.+data ThunkCreateSource+  = ThunkCreateSource_Absolute GitUri+    -- ^ Create a thunk from an absolute reference to a Git repository:+    -- URIs like @file://@, @https://@, @ssh://@ etc.+  | ThunkCreateSource_Relative FilePath+    -- ^ Create a thunk from a local folder. If the folder exists, then+    -- it is made absolute using the current working directory and+    -- treated as a @file://@ URL.+  deriving Show++data ThunkCreateConfig = ThunkCreateConfig+  { _thunkCreateConfig_uri         :: ThunkCreateSource+  , _thunkCreateConfig_branch      :: Maybe (Name Branch)+  , _thunkCreateConfig_rev         :: Maybe (Ref SHA1)+  , _thunkCreateConfig_config      :: ThunkConfig+  , _thunkCreateConfig_destination :: Maybe FilePath+  } deriving Show++data CreateWorktreeConfig = CreateWorktreeConfig+  { _createWorktreeConfig_branch :: Maybe String+  , _createWorktreeConfig_detach :: Bool+  } deriving Show++-- | Convert a GitHub source to a regular Git source. Assumes no submodules.+forgetGithub :: Bool -> GitHubSource -> GitSource+forgetGithub useSsh s = GitSource+  { _gitSource_url = GitUri $ URI.URI+    { URI.uriScheme = Just $ fromRight' $ URI.mkScheme $ if useSsh then "ssh" else "https"+    , URI.uriAuthority = Right $ URI.Authority+        { URI.authUserInfo = URI.UserInfo (fromRight' $ URI.mkUsername "git") Nothing+          <$ guard useSsh+        , URI.authHost = fromRight' $ URI.mkHost "github.com"+        , URI.authPort = Nothing+        }+    , URI.uriPath = Just ( False+                     , fromRight' . URI.mkPathPiece <$>+                       untagName (_gitHubSource_owner s)+                       :| [ untagName (_gitHubSource_repo s) <> ".git" ]+                     )+    , URI.uriQuery = []+    , URI.uriFragment = Nothing+    }+  , _gitSource_branch = _gitHubSource_branch s+  , _gitSource_fetchSubmodules = False+  , _gitSource_private = _gitHubSource_private s+  }++commitNameToRef :: Name Commit -> Ref SHA1+commitNameToRef (N c) = refFromHex $ encodeUtf8 c++-- TODO: Use spinner here.+getNixSha256ForUriUnpacked+  :: MonadNixThunk m+  => GitUri+  -> m NixSha256+getNixSha256ForUriUnpacked uri =+  withExitFailMessage ("nix-prefetch-url: Failed to determine sha256 hash of URL " <> gitUriToText uri) $ do+    [hash] <- fmap T.lines $ readProcessAndLogOutput (Debug, Debug) $+      proc nixPrefetchUrlPath ["--unpack", "--type", "sha256", T.unpack $ gitUriToText uri]+    pure hash++nixPrefetchGit :: MonadNixThunk m => GitUri -> Text -> Bool -> m NixSha256+nixPrefetchGit uri rev fetchSubmodules =+  withExitFailMessage ("nix-prefetch-git: Failed to determine sha256 hash of Git repo " <> gitUriToText uri <> " at " <> rev) $ do+    out <- readProcessAndLogStderr Debug $ ignoreGitConfig $+      proc nixPrefetchGitPath $ filter (/="")+        [ "--url", T.unpack $ gitUriToText uri+        , "--rev", T.unpack rev+        , if fetchSubmodules then "--fetch-submodules" else ""+        , "--quiet"+        ]++    case parseMaybe (Aeson..: "sha256") =<< Aeson.decodeStrict (encodeUtf8 out) of+      Nothing -> failWith $ "nix-prefetch-git: unrecognized output " <> out+      Just x -> pure x++data ReadThunkError+  = ReadThunkError_UnrecognizedThunk+  -- ^ A generic error that can happen while reading a thunk.+  | ReadThunkError_UnrecognizedPaths (Maybe ThunkSpec) (NonEmpty FilePath)+  -- ^ The thunk directory has extraneous paths. The 'Maybe' value+  -- indicates whether we have matched the rest of the files to a valid+  -- specification, and if so, which specification it was.+  | ReadThunkError_MissingPaths (NonEmpty FilePath)+  -- ^ The thunk directory has missing paths.+  | ReadThunkError_UnparseablePtr FilePath String+  -- ^ We could not parse the given file as per the thunk specification.+  -- The 'String' is a parser-specific error message.+  | ReadThunkError_FileError FilePath IOError+  -- ^ We encountered an 'IOError' while reading the given file.+  | ReadThunkError_FileDoesNotMatch FilePath Text+  -- ^ We read the given file just fine, but its contents do not match+  -- what was expected for the specification.+  | ReadThunkError_AmbiguousPackedState ThunkSpec ThunkSpec+  -- ^ We parsed two valid thunk specs for this directory.++-- | Pretty-print a 'ReadThunkError' for display to the user+prettyReadThunkError :: ReadThunkError -> Text+prettyReadThunkError =+  \case+    ReadThunkError_UnrecognizedPaths (Just spec) (f :| fs) ->+      -- Limit to five unrecognised paths so that the user doesn't get+      -- utterly spammed:+      T.unlines ( "The directory matched spec " <> _thunkSpec_name spec <> ", but the following file(s) are extraneous:"+                : map (("  " <>) . T.pack) (f:take 4 fs))+      <> if length fs > 5 then "... and " <> T.pack (show (length fs - 4)) <> " others." else mempty++    ReadThunkError_MissingPaths (f :| fs) ->+      T.unlines $ "The following path(s) are missing from the thunk directory:"+        :map (("  " <>) . T.pack) (f:fs)++    ReadThunkError_FileError path ioe -> "I/O error while reading the file " <> T.pack path <> ":\n" <> T.pack (show ioe)+    ReadThunkError_UnparseablePtr path str -> "Syntax error while reading the file " <> T.pack path <> ":\n" <> T.pack str+    ReadThunkError_FileDoesNotMatch path _ -> "The file " <> T.pack path <> " does not have the right contents for this thunk specification."+    ReadThunkError_AmbiguousPackedState speca specb ->+      "The given thunk directory is ambiguous: It matches both " <> _thunkSpec_name speca <> " and " <> _thunkSpec_name specb <> "."++    ReadThunkError_UnrecognizedThunk -> generic+    ReadThunkError_UnrecognizedPaths{} -> generic+  where+    generic = T.pack "The directory did not match any valid thunk specification.\nRun with -v to see why each spec did not match."++-- | Fail due to a 'ReadThunkError' with a standardised error message.+failReadThunkErrorWhile+  :: MonadError NixThunkError m+  => Text+  -- ^ String describing what we were doing.+  -> ReadThunkError -- ^ The error+  -> m a+failReadThunkErrorWhile what rte = failWith $ "Failure reading thunk " <> what <> ":\n" <> prettyReadThunkError rte++-- | Did we manage to match the thunk directory to one or more known+-- thunk specs before raising this error?+didMatchThunkSpec :: ReadThunkError -> Bool+didMatchThunkSpec (ReadThunkError_UnrecognizedPaths x _) = isJust x+didMatchThunkSpec ReadThunkError_AmbiguousPackedState{} = True+didMatchThunkSpec _ = False++unpackedDirName :: FilePath+unpackedDirName = "."++attrCacheFileName :: FilePath+attrCacheFileName = ".attr-cache"++-- | A path from which our known-good nixpkgs can be fetched.+-- __NOTE__: This path is hardcoded, and only exists so subsumed thunk+-- specs (v7 specifically) can be parsed.+pinnedNixpkgsPath :: FilePath+pinnedNixpkgsPath = "/nix/store/qjg458n31xk1l6lj26c3b871d4i4is98-source"++-- | Specification for how a file in a thunk version works.+data ThunkFileSpec+  = ThunkFileSpec_Ptr (LBS.ByteString -> Either String ThunkPtr) -- ^ This file specifies 'ThunkPtr' data+  | ThunkFileSpec_FileMatches Text -- ^ This file must match the given content exactly+  | ThunkFileSpec_CheckoutIndicator -- ^ Existence of this directory indicates that the thunk is unpacked+  | ThunkFileSpec_AttrCache -- ^ This directory is an attribute cache++-- | Specification for how a set of files in a thunk version work.+data ThunkSpec = ThunkSpec+  { _thunkSpec_name :: !Text+  , _thunkSpec_files :: !(Map FilePath ThunkFileSpec)+  }++thunkSpecTypes :: NonEmpty (NonEmpty ThunkSpec)+thunkSpecTypes = gitThunkSpecs :| [gitHubThunkSpecs]++-- | Attempts to match a 'ThunkSpec' to a given directory.+matchThunkSpecToDir+  :: (MonadError ReadThunkError m, MonadIO m, MonadCatch m)+  => ThunkSpec -- ^ 'ThunkSpec' to match against the given files/directory+  -> FilePath -- ^ Path to directory+  -> Set FilePath -- ^ Set of file paths relative to the given directory+  -> m ThunkData+matchThunkSpecToDir thunkSpec dir dirFiles = do+  isCheckout <- fmap or $ flip Map.traverseWithKey (_thunkSpec_files thunkSpec) $ \expectedPath -> \case+    ThunkFileSpec_CheckoutIndicator -> liftIO (doesDirectoryExist (dir </> expectedPath))+    _ -> pure False+  case isCheckout of+    True -> pure ThunkData_Checkout+    False -> do+      datas <- fmap toList $ flip Map.traverseMaybeWithKey (_thunkSpec_files thunkSpec) $ \expectedPath -> \case+        ThunkFileSpec_AttrCache -> Nothing <$ dirMayExist expectedPath+        ThunkFileSpec_CheckoutIndicator -> pure Nothing -- Handled above+        ThunkFileSpec_FileMatches expectedContents -> handle (\(e :: IOError) -> throwError $ ReadThunkError_FileError expectedPath e) $ do+          actualContents <- liftIO (T.readFile $ dir </> expectedPath)+          case T.strip expectedContents == T.strip actualContents of+            True -> pure Nothing+            False -> throwError $ ReadThunkError_FileDoesNotMatch (dir </> expectedPath) expectedContents+        ThunkFileSpec_Ptr parser -> handle (\(e :: IOError) -> throwError $ ReadThunkError_FileError expectedPath e) $ do+          let path = dir </> expectedPath+          liftIO (doesFileExist path) >>= \case+            False -> pure Nothing+            True -> do+              actualContents <- liftIO $ LBS.readFile path+              case parser actualContents of+                Right v -> pure $ Just (thunkSpec, v)+                Left e -> throwError $ ReadThunkError_UnparseablePtr (dir </> expectedPath) e+      let matched = thunkSpec <$ nonEmpty datas+      for_ (nonEmpty (toList $ dirFiles `Set.difference` expectedPaths)) $ \fs ->+        throwError $ ReadThunkError_UnrecognizedPaths matched $ (dir </>) <$> fs+      for_ (nonEmpty (toList $ requiredPaths `Set.difference` dirFiles)) $ \fs ->+        throwError $ ReadThunkError_MissingPaths $ (dir </>) <$> fs++      uncurry ThunkData_Packed <$> case nonEmpty datas of+        Nothing -> throwError ReadThunkError_UnrecognizedThunk+        Just xs -> fold1WithM xs $ \a@(speca, ptrA) (specb, ptrB) ->+          if ptrA == ptrB then pure a else throwError $ ReadThunkError_AmbiguousPackedState speca specb+  where+    rootPathsOnly = Set.fromList . mapMaybe takeRootDir . Map.keys+    takeRootDir = fmap NonEmpty.head . nonEmpty . splitPath++    expectedPaths = rootPathsOnly $ _thunkSpec_files thunkSpec++    requiredPaths = rootPathsOnly $ Map.filter isRequiredFileSpec $ _thunkSpec_files thunkSpec+    isRequiredFileSpec = \case+      ThunkFileSpec_FileMatches _ -> True+      _ -> False++    dirMayExist expectedPath = liftIO (doesFileExist (dir </> expectedPath)) >>= \case+      True -> throwError $ ReadThunkError_UnrecognizedPaths Nothing $ expectedPath :| []+      False -> pure ()++    fold1WithM (x :| xs) f = foldM f x xs++readThunkWith+  :: (MonadNixThunk m)+  => NonEmpty (NonEmpty ThunkSpec) -> FilePath -> m (Either ReadThunkError ThunkData)+readThunkWith specTypes dir = do+  dirFiles <- Set.fromList <$> liftIO (listDirectory dir)+  let specs = concatMap toList $ toList $ NonEmpty.transpose specTypes -- Interleave spec types so we try each one in a "fair" ordering+  flip fix specs $ \loop -> \case+    [] -> pure $ Left ReadThunkError_UnrecognizedThunk+    spec:rest -> runExceptT (matchThunkSpecToDir spec dir dirFiles) >>= \case+      Left e+        -- If we matched one or more thunk specs, we fail early to tell+        -- the user exactly what's wrong:+        | didMatchThunkSpec e -> pure $ Left e+        -- Otherwise, keep looping:+        | otherwise -> putLog Debug [i|Thunk specification ${_thunkSpec_name spec} did not match ${dir}: ${prettyReadThunkError e}|] *> loop rest+      x@(Right _) -> x <$ putLog Debug [i|Thunk specification ${_thunkSpec_name spec} matched ${dir}|]++-- | Read a packed or unpacked thunk based on predefined thunk specifications.+readThunk :: (MonadNixThunk m) => FilePath -> m (Either ReadThunkError ThunkData)+readThunk = readThunkWith thunkSpecTypes++parseThunkPtr :: (Aeson.Object -> Aeson.Parser ThunkSource) -> Aeson.Object -> Aeson.Parser ThunkPtr+parseThunkPtr parseSrc v = do+  rev <- v Aeson..: "rev"+  sha256 <- v Aeson..: "sha256"+  src <- parseSrc v+  pure $ ThunkPtr+    { _thunkPtr_rev = ThunkRev+      { _thunkRev_commit = refFromHexString rev+      , _thunkRev_nixSha256 = sha256+      }+    , _thunkPtr_source = src+    }++parseGitHubSource :: Aeson.Object -> Aeson.Parser GitHubSource+parseGitHubSource v = do+  owner <- v Aeson..: "owner"+  repo <- v Aeson..: "repo"+  branch <- v Aeson..:! "branch"+  private <- v Aeson..:? "private"+  pure $ GitHubSource+    { _gitHubSource_owner = owner+    , _gitHubSource_repo = repo+    , _gitHubSource_branch = branch+    , _gitHubSource_private = fromMaybe False private+    }++parseGitSource :: Aeson.Object -> Aeson.Parser GitSource+parseGitSource v = do+  Just url <- parseGitUri <$> v Aeson..: "url"+  branch <- v Aeson..:! "branch"+  fetchSubmodules <- v Aeson..:! "fetchSubmodules"+  private <- v Aeson..:? "private"+  pure $ GitSource+    { _gitSource_url = url+    , _gitSource_branch = branch+    , _gitSource_fetchSubmodules = fromMaybe False fetchSubmodules+    , _gitSource_private = fromMaybe False private+    }++overwriteThunk :: MonadNixThunk m => FilePath -> ThunkPtr -> m ()+overwriteThunk target thunk = do+  -- Ensure that this directory is a valid thunk (i.e. so we aren't losing any data)+  readThunk target >>= \case+    Left e -> failReadThunkErrorWhile "while overwriting" e+    Right _ -> pure ()++  --TODO: Is there a safer way to do this overwriting?+  liftIO $ removePathForcibly target+  createThunk target $ Right thunk++thunkPtrToSpec :: ThunkPtr -> ThunkSpec+thunkPtrToSpec thunk = case _thunkPtr_source thunk of+  ThunkSource_GitHub _ -> NonEmpty.head gitHubThunkSpecs+  ThunkSource_Git _ -> NonEmpty.head gitThunkSpecs++-- It's important that formatting be very consistent here, because+-- otherwise when people update thunks, their patches will be messy+encodeThunkPtrData :: ThunkPtr -> LBS.ByteString+encodeThunkPtrData (ThunkPtr rev src) = case src of+  ThunkSource_GitHub s -> encodePretty' githubCfg $ Aeson.object $ catMaybes+    [ Just $ "owner" .= _gitHubSource_owner s+    , Just $ "repo" .= _gitHubSource_repo s+    , ("branch" .=) <$> _gitHubSource_branch s+    , Just $ "rev" .= refToHexString (_thunkRev_commit rev)+    , Just $ "sha256" .= _thunkRev_nixSha256 rev+    , Just $ "private" .= _gitHubSource_private s+    ]+  ThunkSource_Git s -> encodePretty' plainGitCfg $ Aeson.object $ catMaybes+    [ Just $ "url" .= gitUriToText (_gitSource_url s)+    , Just $ "rev" .= refToHexString (_thunkRev_commit rev)+    , ("branch" .=) <$> _gitSource_branch s+    , Just $ "sha256" .= _thunkRev_nixSha256 rev+    , Just $ "fetchSubmodules" .= _gitSource_fetchSubmodules s+    , Just $ "private" .= _gitSource_private s+    ]+ where+  githubCfg = defConfig+    { confIndent = Spaces 2+    , confCompare = keyOrder+        [ "owner"+        , "repo"+        , "branch"+        , "private"+        , "rev"+        , "sha256"+        ] <> compare+    , confTrailingNewline = True+    }+  plainGitCfg = defConfig+    { confIndent = Spaces 2+    , confCompare = keyOrder+        [ "url"+        , "rev"+        , "sha256"+        , "private"+        , "fetchSubmodules"+        ] <> compare+    , confTrailingNewline = True+    }++createThunk' :: MonadNixThunk m => ThunkCreateConfig -> m ()+createThunk' config = do+  newThunkPtr <- thunkCreateSourcePtr+    (_thunkCreateConfig_uri config)+    (_thunkConfig_private $ _thunkCreateConfig_config config)+    (untagName <$> _thunkCreateConfig_branch config)+    (T.pack . show <$> _thunkCreateConfig_rev config)+  let trailingDirectoryName = reverse . takeWhile (/= '/') . dropWhile (=='/') . reverse+      dropDotGit :: FilePath -> FilePath+      dropDotGit origName = fromMaybe origName $ stripExtension "git" origName++      defaultDestinationForGitUri :: GitUri -> FilePath+      defaultDestinationForGitUri = dropDotGit . trailingDirectoryName . T.unpack . URI.render . unGitUri++  destination <- case _thunkCreateConfig_uri config of+    ThunkCreateSource_Absolute uri -> pure $ fromMaybe (defaultDestinationForGitUri uri) $ _thunkCreateConfig_destination config+    ThunkCreateSource_Relative _ -> case _thunkCreateConfig_destination config of+      Nothing -> failWith "When using a relative path as the thunk source, the destination path must be specified."+      Just dst -> pure dst+  createThunk destination $ Right newThunkPtr++createThunk :: MonadNixThunk m => FilePath -> Either ThunkSpec ThunkPtr -> m ()+createThunk target ptrInfo = do+  isdir <- liftIO $ doesDirectoryExist target+  when isdir $ do+    isempty <- null <$> liftIO (listDirectory target)+    unless isempty $ failWith $ "Refusing to create thunk in non-empty directory " <> T.pack target++  ifor_ (_thunkSpec_files spec) $ \path -> \case+    ThunkFileSpec_FileMatches content -> withReadyPath path $ \p -> liftIO $ T.writeFile p content+    ThunkFileSpec_Ptr _ -> case ptrInfo of+      Left _ -> pure () -- We can't write the ptr without it+      Right ptr -> withReadyPath path $ \p -> liftIO $ LBS.writeFile p (encodeThunkPtrData ptr)+    _ -> pure ()+  where+    spec = either id thunkPtrToSpec ptrInfo+    withReadyPath path f = do+      let fullPath = target </> path+      putLog Debug $ "Writing thunk file " <> T.pack fullPath+      liftIO $ createDirectoryIfMissing True $ takeDirectory fullPath+      f fullPath++updateThunkToLatest :: MonadNixThunk m => ThunkUpdateConfig -> FilePath -> m ()+updateThunkToLatest cfg target = do+  withSpinner' ("Updating thunk " <> T.pack target <> " to latest") (pure $ const $ "Thunk " <> T.pack target <> " updated to latest") $ do+    checkThunkDirectory target+    readThunk target >>= \case+      Left err -> failReadThunkErrorWhile "during an update" err+      Right c -> case c of+        ThunkData_Checkout -> failWith [i|Thunk located at ${target} is unpacked. Use 'ob thunk pack' on the desired directory and then try 'ob thunk update' again.|]+        ThunkData_Packed _ t -> case _thunkUpdateConfig_ref cfg of+          Just ref -> do+            newThunkPtr <- uriThunkPtr+              (_gitSource_url $ thunkSourceToGitSource $ _thunkPtr_source t)+              (_thunkConfig_private $ _thunkUpdateConfig_thunk cfg)+              (_thunkUpdateConfig_branch cfg)+              (Just ref)+            overwriteThunk target newThunkPtr+          Nothing -> do+            let newSrc :: ThunkSource+                newSrc = case _thunkUpdateConfig_branch cfg of+                  Nothing -> _thunkPtr_source t+                  Just b -> setThunkSourceBranch (Just $ N b) $ _thunkPtr_source t+            rev <- getLatestRev newSrc+            overwriteThunk target $ modifyThunkPtrByConfig (_thunkUpdateConfig_thunk cfg) $ ThunkPtr+              { _thunkPtr_source = newSrc+              , _thunkPtr_rev = rev+              }++-- | All recognized github standalone loaders, ordered from newest to oldest.+-- This tool will only ever produce the newest one when it writes a thunk.+gitHubThunkSpecs :: NonEmpty ThunkSpec+gitHubThunkSpecs =+  gitHubThunkSpecV8 :|+  [ gitHubThunkSpecV7+  , gitHubThunkSpecV6+  , gitHubThunkSpecV5+  , gitHubThunkSpecV4+  , gitHubThunkSpecV3+  , gitHubThunkSpecV2+  , gitHubThunkSpecV1+  ]++gitHubThunkSpecV1 :: ThunkSpec+gitHubThunkSpecV1 = legacyGitHubThunkSpec "github-v1"+  "import ((import <nixpkgs> {}).fetchFromGitHub (builtins.fromJSON (builtins.readFile ./github.json)))"++gitHubThunkSpecV2 :: ThunkSpec+gitHubThunkSpecV2 = legacyGitHubThunkSpec "github-v2" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE" --TODO: Add something about how to get more info on NixThunk, etc.+  , "import ((import <nixpkgs> {}).fetchFromGitHub ("+  , "  let json = builtins.fromJSON (builtins.readFile ./github.json);"+  , "  in { inherit (json) owner repo rev sha256;"+  , "       private = json.private or false;"+  , "     }"+  , "))"+  ]++gitHubThunkSpecV3 :: ThunkSpec+gitHubThunkSpecV3 = legacyGitHubThunkSpec "github-v3" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE"+  , "let"+  , "  fetch = { private ? false, ... }@args: if private && builtins.hasAttr \"fetchGit\" builtins"+  , "    then fetchFromGitHubPrivate args"+  , "    else (import <nixpkgs> {}).fetchFromGitHub (builtins.removeAttrs args [\"branch\"]);"+  , "  fetchFromGitHubPrivate ="+  , "    { owner, repo, rev, branch ? null, name ? null, sha256 ? null, private ? false"+  , "    , fetchSubmodules ? false, githubBase ? \"github.com\", ..."+  , "    }: assert !fetchSubmodules;"+  , "      builtins.fetchGit ({"+  , "        url = \"ssh://git@${githubBase}/${owner}/${repo}.git\";"+  , "        inherit rev;"+  , "      }"+  , "      // (if branch == null then {} else { ref = branch; })"+  , "      // (if name == null then {} else { inherit name; }));"+  , "in import (fetch (builtins.fromJSON (builtins.readFile ./github.json)))"+  ]++gitHubThunkSpecV4 :: ThunkSpec+gitHubThunkSpecV4 = legacyGitHubThunkSpec "github-v4" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE"+  , "let fetch = { private ? false, fetchSubmodules ? false, owner, repo, rev, sha256, ... }:"+  , "  if !fetchSubmodules && !private then builtins.fetchTarball {"+  , "    url = \"https://github.com/${owner}/${repo}/archive/${rev}.tar.gz\"; inherit sha256;"+  , "  } else (import <nixpkgs> {}).fetchFromGitHub {"+  , "    inherit owner repo rev sha256 fetchSubmodules private;"+  , "  };"+  , "in import (fetch (builtins.fromJSON (builtins.readFile ./github.json)))"+  ]++legacyGitHubThunkSpec :: Text -> Text -> ThunkSpec+legacyGitHubThunkSpec name loader = ThunkSpec name $ Map.fromList+  [ ("default.nix", ThunkFileSpec_FileMatches $ T.strip loader)+  , ("github.json" , ThunkFileSpec_Ptr parseGitHubJsonBytes)+  , (attrCacheFileName, ThunkFileSpec_AttrCache)+  , (".git", ThunkFileSpec_CheckoutIndicator)+  ]++gitHubThunkSpecV5 :: ThunkSpec+gitHubThunkSpecV5 = mkThunkSpec "github-v5" "github.json" parseGitHubJsonBytes [here|+# DO NOT HAND-EDIT THIS FILE+let fetch = { private ? false, fetchSubmodules ? false, owner, repo, rev, sha256, ... }:+  if !fetchSubmodules && !private then builtins.fetchTarball {+    url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz"; inherit sha256;+  } else (import <nixpkgs> {}).fetchFromGitHub {+    inherit owner repo rev sha256 fetchSubmodules private;+  };+  json = builtins.fromJSON (builtins.readFile ./github.json);+in fetch json+|]++-- | See 'gitHubThunkSpecV7'.+--+-- __NOTE__: v6 spec thunks are broken! They import the pinned nixpkgs+-- in an incorrect way. GitHub thunks for public repositories with no+-- submodules will still work, but update as soon as possible.+gitHubThunkSpecV6 :: ThunkSpec+gitHubThunkSpecV6 = mkThunkSpec "github-v6" "github.json" parseGitHubJsonBytes [here|+# DO NOT HAND-EDIT THIS FILE+let fetch = { private ? false, fetchSubmodules ? false, owner, repo, rev, sha256, ... }:+  if !fetchSubmodules && !private then builtins.fetchTarball {+    url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz"; inherit sha256;+  } else (builtins.fetchTarball {+  url = "https://github.com/NixOS/nixpkgs/archive/3aad50c30c826430b0270fcf8264c8c41b005403.tar.gz";+  sha256 = "0xwqsf08sywd23x0xvw4c4ghq0l28w2ki22h0bdn766i16z9q2gr";+}).fetchFromGitHub {+    inherit owner repo rev sha256 fetchSubmodules private;+  };+  json = builtins.fromJSON (builtins.readFile ./github.json);+in fetch json+|]++-- | Specification for GitHub thunks which use a specific, pinned+-- version of nixpkgs for fetching, rather than using @<nixpkgs>@ from+-- @NIX_PATH@. The "v7" specs ensure that thunks can be fetched even+-- when @NIX_PATH@ is unset.+gitHubThunkSpecV7 :: ThunkSpec+gitHubThunkSpecV7 = mkThunkSpec "github-v7" "github.json" parseGitHubJsonBytes [i|# DO NOT HAND-EDIT THIS FILE+let fetch = { private ? false, fetchSubmodules ? false, owner, repo, rev, sha256, ... }:+  if !fetchSubmodules && !private then builtins.fetchTarball {+    url = "https://github.com/\${owner}/\${repo}/archive/\${rev}.tar.gz"; inherit sha256;+  } else (import ${pinnedNixpkgsPath} {}).fetchFromGitHub {+    inherit owner repo rev sha256 fetchSubmodules private;+  };+  json = builtins.fromJSON (builtins.readFile ./github.json);+in fetch json|]++-- | Specification for GitHub thunks which use a specific, pinned+-- version of nixpkgs for fetching, rather than using @<nixpkgs>@ from+-- @NIX_PATH@.+--+-- Unlike 'gitHubThunKSpecV7', this thunk specification fetches the+-- nixpkgs tarball from GitHub, so it will fail on environments without+-- a network connection.+gitHubThunkSpecV8 :: ThunkSpec+gitHubThunkSpecV8 = mkThunkSpec "github-v8" "github.json" parseGitHubJsonBytes [here|+# DO NOT HAND-EDIT THIS FILE+let fetch = { private ? false, fetchSubmodules ? false, owner, repo, rev, sha256, ... }:+  if !fetchSubmodules && !private then builtins.fetchTarball {+    url = "https://github.com/${owner}/${repo}/archive/${rev}.tar.gz"; inherit sha256;+  } else (import (builtins.fetchTarball {+  url = "https://github.com/NixOS/nixpkgs/archive/3aad50c30c826430b0270fcf8264c8c41b005403.tar.gz";+  sha256 = "0xwqsf08sywd23x0xvw4c4ghq0l28w2ki22h0bdn766i16z9q2gr";+}) {}).fetchFromGitHub {+    inherit owner repo rev sha256 fetchSubmodules private;+  };+  json = builtins.fromJSON (builtins.readFile ./github.json);+in fetch json+|]++parseGitHubJsonBytes :: LBS.ByteString -> Either String ThunkPtr+parseGitHubJsonBytes = parseJsonObject $ parseThunkPtr $ \v ->+  ThunkSource_GitHub <$> parseGitHubSource v <|> ThunkSource_Git <$> parseGitSource v++gitThunkSpecs :: NonEmpty ThunkSpec+gitThunkSpecs =+  gitThunkSpecV9 :|+  [ gitThunkSpecV8+  , gitThunkSpecV7+  , gitThunkSpecV6+  , gitThunkSpecV5+  , gitThunkSpecV4+  , gitThunkSpecV3+  , gitThunkSpecV2+  , gitThunkSpecV1+  ]++gitThunkSpecV1 :: ThunkSpec+gitThunkSpecV1 = legacyGitThunkSpec "git-v1" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE"+  , "let fetchGit = {url, rev, ref ? null, branch ? null, sha256 ? null, fetchSubmodules ? null}:"+  , "  assert !fetchSubmodules; (import <nixpkgs> {}).fetchgit { inherit url rev sha256; };"+  , "in import (fetchGit (builtins.fromJSON (builtins.readFile ./git.json)))"+  ]++gitThunkSpecV2 :: ThunkSpec+gitThunkSpecV2 = legacyGitThunkSpec "git-v2" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE"+  , "let fetchGit = {url, rev, ref ? null, branch ? null, sha256 ? null, fetchSubmodules ? null}:"+  , "  if builtins.hasAttr \"fetchGit\" builtins"+  , "    then builtins.fetchGit ({ inherit url rev; } // (if branch == null then {} else { ref = branch; }))"+  , "    else abort \"Plain Git repositories are only supported on nix 2.0 or higher.\";"+  , "in import (fetchGit (builtins.fromJSON (builtins.readFile ./git.json)))"+  ]++-- This loader has a bug because @builtins.fetchGit@ is not given a @ref@+-- and will fail to find commits without this because it does shallow clones.+gitThunkSpecV3 :: ThunkSpec+gitThunkSpecV3 = legacyGitThunkSpec "git-v3" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE"+  , "let fetch = {url, rev, ref ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:"+  , "  let realUrl = let firstChar = builtins.substring 0 1 url; in"+  , "    if firstChar == \"/\" then /. + url"+  , "    else if firstChar == \".\" then ./. + url"+  , "    else url;"+  , "  in if !fetchSubmodules && private then builtins.fetchGit {"+  , "    url = realUrl; inherit rev;"+  , "  } else (import <nixpkgs> {}).fetchgit {"+  , "    url = realUrl; inherit rev sha256;"+  , "  };"+  , "in import (fetch (builtins.fromJSON (builtins.readFile ./git.json)))"+  ]++gitThunkSpecV4 :: ThunkSpec+gitThunkSpecV4 = legacyGitThunkSpec "git-v4" $ T.unlines+  [ "# DO NOT HAND-EDIT THIS FILE"+  , "let fetch = {url, rev, branch ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:"+  , "  let realUrl = let firstChar = builtins.substring 0 1 url; in"+  , "    if firstChar == \"/\" then /. + url"+  , "    else if firstChar == \".\" then ./. + url"+  , "    else url;"+  , "  in if !fetchSubmodules && private then builtins.fetchGit {"+  , "    url = realUrl; inherit rev;"+  , "    ${if branch == null then null else \"ref\"} = branch;"+  , "  } else (import <nixpkgs> {}).fetchgit {"+  , "    url = realUrl; inherit rev sha256;"+  , "  };"+  , "in import (fetch (builtins.fromJSON (builtins.readFile ./git.json)))"+  ]++legacyGitThunkSpec :: Text -> Text -> ThunkSpec+legacyGitThunkSpec name loader = ThunkSpec name $ Map.fromList+  [ ("default.nix", ThunkFileSpec_FileMatches $ T.strip loader)+  , ("git.json" , ThunkFileSpec_Ptr parseGitJsonBytes)+  , (attrCacheFileName, ThunkFileSpec_AttrCache)+  , (".git", ThunkFileSpec_CheckoutIndicator)+  ]++gitThunkSpecV5 :: ThunkSpec+gitThunkSpecV5 = mkThunkSpec "git-v5" "git.json" parseGitJsonBytes [here|+# DO NOT HAND-EDIT THIS FILE+let fetch = {url, rev, branch ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:+  let realUrl = let firstChar = builtins.substring 0 1 url; in+    if firstChar == "/" then /. + url+    else if firstChar == "." then ./. + url+    else url;+  in if !fetchSubmodules && private then builtins.fetchGit {+    url = realUrl; inherit rev;+    ${if branch == null then null else "ref"} = branch;+  } else (import <nixpkgs> {}).fetchgit {+    url = realUrl; inherit rev sha256;+  };+  json = builtins.fromJSON (builtins.readFile ./git.json);+in fetch json+|]++-- | See 'gitThunkSpecV7'.+-- __NOTE__: v6 spec thunks are broken! They import the pinned nixpkgs+-- in an incorrect way. GitHub thunks for public repositories with no+-- submodules will still work, but update as soon as possible.+gitThunkSpecV6 :: ThunkSpec+gitThunkSpecV6 = mkThunkSpec "git-v6" "git.json" parseGitJsonBytes [here|+# DO NOT HAND-EDIT THIS FILE+let fetch = {url, rev, branch ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:+  let realUrl = let firstChar = builtins.substring 0 1 url; in+    if firstChar == "/" then /. + url+    else if firstChar == "." then ./. + url+    else url;+  in if !fetchSubmodules && private then builtins.fetchGit {+    url = realUrl; inherit rev;+    ${if branch == null then null else "ref"} = branch;+  } else (builtins.fetchTarball {+  url = "https://github.com/NixOS/nixpkgs/archive/3aad50c30c826430b0270fcf8264c8c41b005403.tar.gz";+  sha256 = "0xwqsf08sywd23x0xvw4c4ghq0l28w2ki22h0bdn766i16z9q2gr";+}).fetchgit {+    url = realUrl; inherit rev sha256;+  };+  json = builtins.fromJSON (builtins.readFile ./git.json);+in fetch json+|]++-- | Specification for Git thunks which use a specific, pinned version+-- of nixpkgs for fetching, rather than using @<nixpkgs>@ from+-- @NIX_PATH@. The "v7" specs ensure that thunks can be fetched even+-- when @NIX_PATH@ is unset.+gitThunkSpecV7 :: ThunkSpec+gitThunkSpecV7 = mkThunkSpec "git-v7" "git.json" parseGitJsonBytes [i|# DO NOT HAND-EDIT THIS FILE+let fetch = {url, rev, branch ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:+  let realUrl = let firstChar = builtins.substring 0 1 url; in+    if firstChar == "/" then /. + url+    else if firstChar == "." then ./. + url+    else url;+  in if !fetchSubmodules && private then builtins.fetchGit {+    url = realUrl; inherit rev;+    \${if branch == null then null else "ref"} = branch;+  } else (import ${pinnedNixpkgsPath} {}).fetchgit {+    url = realUrl; inherit rev sha256;+  };+  json = builtins.fromJSON (builtins.readFile ./git.json);+in fetch json|]++-- | Specification for Git thunks which use a specific, pinned version+-- version of nixpkgs for fetching, rather than using @<nixpkgs>@ from+-- @NIX_PATH@.+--+-- Unlike 'gitHubThunKSpecV7', this thunk specification fetches the+-- nixpkgs tarball from GitHub, so it will fail on environments without+-- a network connection.+gitThunkSpecV8 :: ThunkSpec+gitThunkSpecV8 = mkThunkSpec "git-v8" "git.json" parseGitJsonBytes [i|# DO NOT HAND-EDIT THIS FILE+let fetch = {url, rev, branch ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:+  let realUrl = let firstChar = builtins.substring 0 1 url; in+    if firstChar == "/" then /. + url+    else if firstChar == "." then ./. + url+    else url;+  in if !fetchSubmodules && private then builtins.fetchGit {+    url = realUrl; inherit rev;+    \${if branch == null then null else "ref"} = branch;+  } else (import (builtins.fetchTarball {+  url = "https://github.com/NixOS/nixpkgs/archive/3aad50c30c826430b0270fcf8264c8c41b005403.tar.gz";+  sha256 = "0xwqsf08sywd23x0xvw4c4ghq0l28w2ki22h0bdn766i16z9q2gr";+}) {}).fetchgit {+    url = realUrl; inherit rev sha256;+  };+  json = builtins.fromJSON (builtins.readFile ./git.json);+in fetch json|]++-- | Improves V8 by supporting retrieving revs from any branch, when a branch is not provided+-- Previously, it would only work for revs that were present on the default branch+gitThunkSpecV9 :: ThunkSpec+gitThunkSpecV9 = mkThunkSpec "git-v9" "git.json" parseGitHubJsonBytes [here|+# DO NOT HAND-EDIT THIS FILE+let fetch = {url, rev, branch ? null, sha256 ? null, fetchSubmodules ? false, private ? false, ...}:+  let realUrl = let firstChar = builtins.substring 0 1 url; in+    if firstChar == "/" then /. + url+    else if firstChar == "." then ./. + url+    else url;+  in if !fetchSubmodules && private then builtins.fetchGit {+    url = realUrl; inherit rev;+    ${if branch == null then null else "ref"} = branch;+    allRefs = branch == null;+  } else (import (builtins.fetchTarball {+    url = "https://github.com/NixOS/nixpkgs/archive/3aad50c30c826430b0270fcf8264c8c41b005403.tar.gz";+    sha256 = "0xwqsf08sywd23x0xvw4c4ghq0l28w2ki22h0bdn766i16z9q2gr";+  }) {}).fetchgit {+    url = realUrl; inherit rev sha256;+  };+  json = builtins.fromJSON (builtins.readFile ./git.json);+in fetch json+|]++parseGitJsonBytes :: LBS.ByteString -> Either String ThunkPtr+parseGitJsonBytes = parseJsonObject $ parseThunkPtr $ fmap ThunkSource_Git . parseGitSource++mkThunkSpec :: Text -> FilePath -> (LBS.ByteString -> Either String ThunkPtr) -> Text -> ThunkSpec+mkThunkSpec name jsonFileName parser srcNix = ThunkSpec name $ Map.fromList+  [ ("default.nix", ThunkFileSpec_FileMatches defaultNixViaSrc)+  , ("thunk.nix", ThunkFileSpec_FileMatches srcNix)+  , (jsonFileName, ThunkFileSpec_Ptr parser)+  , (attrCacheFileName, ThunkFileSpec_AttrCache)+  , (normalise $ unpackedDirName </> ".git", ThunkFileSpec_CheckoutIndicator)+  ]+  where+    defaultNixViaSrc = [here|+# DO NOT HAND-EDIT THIS FILE+import (import ./thunk.nix)+|]+++parseJsonObject :: (Aeson.Object -> Aeson.Parser a) -> LBS.ByteString -> Either String a+parseJsonObject p bytes = Aeson.parseEither p =<< Aeson.eitherDecode bytes++-- | Checks a cache directory to see if there is a fresh symlink+-- to the result of building an attribute of a thunk.+-- If no cache hit is found, nix-build is called to build the attribute+-- and the result is symlinked into the cache.+nixBuildThunkAttrWithCache+  :: ( MonadIO m+     , MonadLog Output m+     , HasCliConfig NixThunkError m+     , MonadMask m+     , MonadError NixThunkError m+     , MonadFail m+     )+  => ThunkSpec+  -> FilePath+  -- ^ Path to directory containing Thunk+  -> String+  -- ^ Attribute to build+  -> m (Maybe FilePath)+  -- ^ Symlink to cached or built nix output+-- WARNING: If the thunk uses an impure reference such as '<nixpkgs>'+-- the caching mechanism will fail as it merely measures the modification+-- time of the cache link and the expression to build.+nixBuildThunkAttrWithCache thunkSpec thunkDir attr = do+  latestChange <- liftIO $ do+    let+      getModificationTimeMaybe = fmap rightToMaybe . try @IOError . getModificationTime+      thunkFileNames = L.delete attrCacheFileName $ Map.keys $ _thunkSpec_files thunkSpec+    maximum . catMaybes <$> traverse (getModificationTimeMaybe . (thunkDir </>)) thunkFileNames++  let cachePaths' = nonEmpty $ Map.keys $ Map.filter (\case ThunkFileSpec_AttrCache -> True; _ -> False) $+                      _thunkSpec_files thunkSpec+  for cachePaths' $ \cachePaths ->+    fmap NonEmpty.head $ for cachePaths $ \cacheDir -> do+      let+        cachePath = thunkDir </> cacheDir </> attr <.> "out"+        cacheErrHandler e+          | isDoesNotExistError e = pure Nothing -- expected from a cache miss+          | otherwise = Nothing <$ putLog Error (T.pack $ displayException e)+      cacheHit <- handle cacheErrHandler $ do+        cacheTime <- liftIO $ posixSecondsToUTCTime . realToFrac . modificationTime <$> getSymbolicLinkStatus cachePath+        pure $ if latestChange <= cacheTime+          then Just cachePath+          else Nothing+      case cacheHit of+        Just c -> pure c+        Nothing -> do+          putLog Warning $ T.pack $ mconcat [thunkDir, ": ", attr, " not cached, building ..."]+          liftIO $ createDirectoryIfMissing True (takeDirectory cachePath)+          (cachePath <$) $ nixCmd $ NixCmd_Build $ def+            & nixBuildConfig_outLink .~ OutLink_IndirectRoot cachePath+            & nixCmdConfig_target .~ Target+              { _target_path = Just thunkDir+              , _target_attr = Just attr+              , _target_expr = Nothing+              }++-- | Build a nix attribute, and cache the result if possible+nixBuildAttrWithCache+  :: ( MonadLog Output m+     , HasCliConfig NixThunkError m+     , MonadIO m+     , MonadMask m+     , MonadError NixThunkError m+     , MonadFail m+     )+  => FilePath+  -- ^ Path to directory containing Thunk+  -> String+  -- ^ Attribute to build+  -> m FilePath+  -- ^ Symlink to cached or built nix output+nixBuildAttrWithCache exprPath attr = readThunk exprPath >>= \case+  -- Only packed thunks are cached. In particular, checkouts are not.+  Right (ThunkData_Packed spec _) ->+    maybe build pure =<< nixBuildThunkAttrWithCache spec exprPath attr+  _ -> build+  where+    build = nixCmd $ NixCmd_Build $ def+      & nixBuildConfig_outLink .~ OutLink_None+      & nixCmdConfig_target .~ Target+        { _target_path = Just exprPath+        , _target_attr = Just attr+        , _target_expr = Nothing+        }++-- | Safely update thunk using a custom action+--+-- A temporary working space is used to do any update. When the custom+-- action successfully completes, the resulting (packed) thunk is copied+-- back to the original location.+updateThunk :: MonadNixThunk m => FilePath -> (FilePath -> m a) -> m a+updateThunk p f = withSystemTempDirectory "obelisk-thunkptr-" $ \tmpDir -> do+  p' <- copyThunkToTmp tmpDir p+  unpackThunk' True p'+  result <- f p'+  updateThunkFromTmp p'+  return result+  where+    copyThunkToTmp tmpDir thunkDir = readThunk thunkDir >>= \case+      Left err -> failReadThunkErrorWhile "during an update" err+      Right ThunkData_Packed{} -> do+        let tmpThunk = tmpDir </> "thunk"+        callProcessAndLogOutput (Notice, Error) $+          proc cp ["-r", "-T", thunkDir, tmpThunk]+        return tmpThunk+      Right _ -> failWith "Thunk is not packed"+    updateThunkFromTmp p' = do+      _ <- packThunk' True (ThunkPackConfig False (ThunkConfig Nothing)) p'+      callProcessAndLogOutput (Notice, Error) $+        proc cp ["-r", "-T", p', p]++finalMsg :: Bool -> (a -> Text) -> Maybe (a -> Text)+finalMsg noTrail s = if noTrail then Nothing else Just s++-- | Check that we are not somewhere inside the thunk directory+checkThunkDirectory :: MonadNixThunk m => FilePath -> m ()+checkThunkDirectory thunkDir = do+  currentDir <- liftIO getCurrentDirectory+  thunkDir' <- liftIO $ canonicalizePath thunkDir+  when (thunkDir' `L.isInfixOf` currentDir) $+    failWith [i|Can't perform thunk operations from within the thunk directory: ${thunkDir}|]++  -- Don't let thunk commands work when directly given an unpacked repo+  when (takeFileName thunkDir == unpackedDirName) $+    readThunk (takeDirectory thunkDir) >>= \case+      Right _ -> failWith [i|Refusing to perform thunk operation on ${thunkDir} because it is a thunk's unpacked source|]+      Left _ -> pure ()++unpackThunk :: MonadNixThunk m => FilePath -> m ()+unpackThunk = unpackThunk' False++unpackThunk' :: MonadNixThunk m => Bool -> FilePath -> m ()+unpackThunk' noTrail thunkDir = checkThunkDirectory thunkDir *> readThunk thunkDir >>= \case+  Left err -> failReadThunkErrorWhile "while unpacking" err+  --TODO: Overwrite option that rechecks out thunk; force option to do so even if working directory is dirty+  Right ThunkData_Checkout -> failWith [i|Thunk at ${thunkDir} is already unpacked|]+  Right (ThunkData_Packed _ tptr) -> do+    let (thunkParent, thunkName) = splitFileName thunkDir+    withTempDirectory thunkParent thunkName $ \tmpThunk -> do+      let+        gitSrc = thunkSourceToGitSource $ _thunkPtr_source tptr+        newSpec = case _thunkPtr_source tptr of+          ThunkSource_GitHub _ -> NonEmpty.head gitHubThunkSpecs+          ThunkSource_Git _ -> NonEmpty.head gitThunkSpecs+      withSpinner' ("Fetching thunk " <> T.pack thunkName)+                   (finalMsg noTrail $ const $ "Fetched thunk " <> T.pack thunkName) $ do+        let unpackedPath = tmpThunk </> unpackedDirName+        gitCloneForThunkUnpack gitSrc (_thunkRev_commit $ _thunkPtr_rev tptr) unpackedPath++        let normalizeMore = dropTrailingPathSeparator . normalise+        when (normalizeMore unpackedPath /= normalizeMore tmpThunk) $ -- Only write meta data if the checkout is not inplace+          createThunk tmpThunk $ Left newSpec++        liftIO $ do+          removePathForcibly thunkDir+          renameDirectory tmpThunk thunkDir++gitCloneForThunkUnpack+  :: MonadNixThunk m+  => GitSource -- ^ Git source to use+  -> Ref hash -- ^ Commit hash to reset to+  -> FilePath -- ^ Directory to clone into+  -> m ()+gitCloneForThunkUnpack gitSrc commit dir = do+  _ <- readGitProcess dir $ [ "clone" ]+    ++  ["--recursive" | _gitSource_fetchSubmodules gitSrc]+    ++  [ T.unpack $ gitUriToText $ _gitSource_url gitSrc ]+    ++  do branch <- maybeToList $ _gitSource_branch gitSrc+           [ "--branch", T.unpack $ untagName branch ]+  _ <- readGitProcess dir ["reset", "--hard", refToHexString commit]+  when (_gitSource_fetchSubmodules gitSrc) $+    void $ readGitProcess dir ["submodule", "update", "--recursive", "--init"]++createWorktree :: MonadNixThunk m => FilePath -> FilePath -> CreateWorktreeConfig -> m ()+createWorktree thunkDir gitDir config = checkThunkDirectory thunkDir *> readThunk thunkDir >>= \case+  Left err -> failReadThunkErrorWhile "while creating worktree" err+  Right ThunkData_Checkout -> failWith [i|Thunk at ${thunkDir} is already unpacked|]+  Right (ThunkData_Packed _ tptr) -> do++    ensureGitRevExist gitDir tptr++    let (thunkParent, thunkName) = splitFileName thunkDir+    withTempDirectory thunkParent thunkName $ \tmpThunk -> do+      withSpinner' ("Creating worktree for " <> T.pack thunkName)+                   (Just (const $ "Created worktree for " <> T.pack thunkName)) $ do+        currentDir <- liftIO getCurrentDirectory+        let worktreePath = currentDir </> tmpThunk </> unpackedDirName+            thunkFullPath = currentDir </> thunkDir </> unpackedDirName++            -- Create a new branch with the user specified name if provided+            -- else fallback to the branch specified in thunk+            -- If a local branch already exists in gitDir, the worktree creation will fail+            -- In which case the user should specify an alternate branch or use "-d"+            mBranchName = case _createWorktreeConfig_branch config of+              Just b -> Just b+              _ -> T.unpack . untagName <$> _gitSource_branch (thunkSourceToGitSource $ _thunkPtr_source tptr)++        _ <- readGitProcess gitDir $+          [ "worktree", "add"+          , worktreePath+          , refToHexString (_thunkRev_commit $ _thunkPtr_rev tptr)+          ] ++ (if _createWorktreeConfig_detach config+                then ["-d"]+                else maybe [] (\b -> ["-b",  b]) mBranchName)++        liftIO $ removePathForcibly thunkDir++        _ <- readGitProcess gitDir+          [ "worktree", "move"+          , normalise worktreePath+          , normalise thunkFullPath]+        pure ()++-- | Ensures that the git repo contains the revision specified in the ThunkPtr+-- by doing fetch from remote if necessary.+ensureGitRevExist :: MonadNixThunk m => FilePath -> ThunkPtr -> m ()+ensureGitRevExist gitDir tptr = do+  isdir <- liftIO $ doesDirectoryExist gitDir+  -- check .git+  unless isdir $ failWith $ "Git directory does not exist: " <> T.pack gitDir++  (exitCode, _, _) <- readCreateProcessWithExitCode $+    gitProc gitDir+      [ "reflog"+      , "exists"+      , refToHexString (_thunkRev_commit $ _thunkPtr_rev tptr)+      ]++  when (exitCode /= ExitSuccess) $ do+    void $ readGitProcess gitDir+      [ "fetch"+      , T.unpack $ gitUriToText (_gitSource_url $ thunkSourceToGitSource $ _thunkPtr_source tptr)+      , refToHexString (_thunkRev_commit $ _thunkPtr_rev tptr)+      ]+++-- | Read a git process ignoring the global configuration (according to 'ignoreGitConfig').+readGitProcess :: MonadNixThunk m => FilePath -> [String] -> m Text+readGitProcess dir = readProcessAndLogOutput (Notice, Notice) . ignoreGitConfig . gitProc dir++-- | Prevent the called process from reading Git configuration. This+-- isn't as locked-down as 'isolateGitProc' to make sure the Git process+-- can still interact with the user (e.g. @ssh-askpass@), but it still+-- ignores enough of the configuration to ensure that thunks are+-- reproducible.+ignoreGitConfig :: ProcessSpec -> ProcessSpec+ignoreGitConfig = setEnvOverride (envfix <>)+  where+    -- Ignore both global (user's) and system (... system-wide) git+    -- configuration.+    envfix = Map.fromList+      [ ("GIT_CONFIG_NOSYSTEM", "yes")+      -- Git documentation says GIT_CONFIG_GLOBAL=/dev/null should+      -- prevent it from reading the global config file but that's a+      -- lie, actually.+      , ("HOME", "/dev/null")+      , ("XDG_CONFIG_HOME", "/dev/null")+      ]++--TODO: add a rollback mode to pack to the original thunk+packThunk :: MonadNixThunk m => ThunkPackConfig -> FilePath -> m ThunkPtr+packThunk = packThunk' False++packThunk' :: MonadNixThunk m => Bool -> ThunkPackConfig -> FilePath -> m ThunkPtr+packThunk' noTrail (ThunkPackConfig force thunkConfig) thunkDir = checkThunkDirectory thunkDir *> readThunk thunkDir >>= \case+  Right ThunkData_Packed{} -> failWith [i|Thunk at ${thunkDir} is is already packed|]+  _ -> withSpinner'+    ("Packing thunk " <> T.pack thunkDir)+    (finalMsg noTrail $ const $ "Packed thunk " <> T.pack thunkDir) $+    do+      let checkClean = if force then CheckClean_NoCheck else CheckClean_FullCheck+      (thunkPtr, isWorktree) <- first (modifyThunkPtrByConfig thunkConfig)+        <$> getThunkPtr checkClean thunkDir (_thunkConfig_private thunkConfig)+      if isWorktree+        then void $ do+          -- Remove the branch locally, and then remove the worktree+          case _gitSource_branch $ thunkSourceToGitSource $ _thunkPtr_source thunkPtr of+            Just branch -> do+              void $ readGitProcess thunkDir ["switch", "--detach"]+              void $ readGitProcess thunkDir ["branch", "-d", T.unpack $ untagName branch]+            Nothing -> pure () -- Should never happen+          readGitProcess thunkDir ["worktree", "remove", "."]+        else liftIO $ removePathForcibly thunkDir+      createThunk thunkDir $ Right thunkPtr+      pure thunkPtr++modifyThunkPtrByConfig :: ThunkConfig -> ThunkPtr -> ThunkPtr+modifyThunkPtrByConfig (ThunkConfig markPrivate') ptr = case markPrivate' of+  Nothing -> ptr+  Just markPrivate -> ptr { _thunkPtr_source = case _thunkPtr_source ptr of+      ThunkSource_Git s -> ThunkSource_Git $ s { _gitSource_private = markPrivate }+      ThunkSource_GitHub s -> ThunkSource_GitHub $ s { _gitHubSource_private = markPrivate }+    }++data CheckClean+  = CheckClean_FullCheck+  -- ^ Check that the repo is clean, including .gitignored files+  | CheckClean_NotIgnored+  -- ^ Check that the repo is clean, not including .gitignored files+  | CheckClean_NoCheck+  -- ^ Don't check that the repo is clean++getThunkPtr :: forall m. MonadNixThunk m => CheckClean -> FilePath -> Maybe Bool -> m (ThunkPtr, Bool)+getThunkPtr gitCheckClean dir mPrivate = do+  let repoLocations = nubOrd $ map (first normalise)+        [(".git", "."), (unpackedDirName </> ".git", unpackedDirName)]+  repoLocation' <- liftIO $ flip findM repoLocations $ doesDirectoryExist . (dir </>) . fst+  (thunkDir, isWorktree) <- case repoLocation' of+    Nothing -> do+      ff <- liftIO $ flip findM repoLocations $ doesFileExist . (dir </>) . fst+      case ff of+        Nothing -> failWith [i|Can't find an unpacked thunk in ${dir}|]+        Just (gitPath, path) -> do+          putLog Informational "Couldn't find .git dir, looking for a worktree instead"+          fileContents <- liftIO $ T.readFile (dir </> gitPath)+          unless (T.isPrefixOf "gitdir: " fileContents) $ failWith [i|Can't find an unpacked thunk or worktree in ${dir}|]+          pure (normalise $ dir </> path, True)+    Just (_, path) -> pure (normalise $ dir </> path, False)++  let (checkClean, checkIgnored) = case gitCheckClean of+        CheckClean_FullCheck -> (True, True)+        CheckClean_NotIgnored -> (True, False)+        CheckClean_NoCheck -> (False, False)+  when checkClean $ ensureCleanGitRepo thunkDir checkIgnored+    "thunk pack: thunk checkout contains unsaved modifications"++  -- Check whether there are any stashes+  when (checkClean && not isWorktree) $ do+    stashOutput <- readGitProcess thunkDir ["stash", "list"]+    unless (T.null stashOutput) $+      failWith $ T.unlines $+        [ "thunk pack: thunk checkout has stashes"+        , "git stash list:"+        ] ++ T.lines stashOutput++  -- Get current branch+  (mCurrentBranch, mCurrentCommit) <- do+    b <- listToMaybe . T.lines <$> readGitProcess thunkDir ["rev-parse", "--abbrev-ref", "HEAD"]+    c <- listToMaybe . T.lines <$> readGitProcess thunkDir ["rev-parse", "HEAD"]+    case b of+      (Just "HEAD") -> failWith $ T.unlines+        [ "thunk pack: You are in 'detached HEAD' state."+        , "If you want to pack at the current ref \+          \then please create a new branch with 'git checkout -b <new-branch-name>' and push this upstream."+        ]+      _ -> return (b, c)++  let refs = if isWorktree+        -- Get information on current branch only+        then "refs/heads/" <> maybe "" T.unpack mCurrentBranch+        -- Get information on all branches and their (optional) designated+        -- upstream correspondents+        else "refs/heads/"+  headDump :: [Text] <- T.lines <$> readGitProcess thunkDir+    [ "for-each-ref"+    , "--format=%(refname:short) %(upstream:short) %(upstream:remotename)"+    , refs+    ]++  (headInfo :: Map Text (Maybe (Text, Text)))+    <- fmap Map.fromList $ forM headDump $ \line -> do+      (branch : restOfLine) <- pure $ T.words line+      mUpstream <- case restOfLine of+        [] -> pure Nothing+        [u, r] -> pure $ Just (u, r)+        (_:_) -> failWith "git for-each-ref invalid output"+      pure (branch, mUpstream)++  putLog Debug $ "branches: " <> T.pack (show headInfo)++  let errorMap :: Map Text ()+      headUpstream :: Map Text (Text, Text)+      (errorMap, headUpstream) = flip Map.mapEither headInfo $ \case+        Nothing -> Left ()+        Just b -> Right b++  putLog Debug $ "branches with upstream branch set: " <> T.pack (show headUpstream)++  -- Check that every branch has a remote equivalent+  when checkClean $ do+    let untrackedBranches = Map.keys errorMap+    when (not $ L.null untrackedBranches) $ failWith $ T.unlines $+      [ "thunk pack: Certain branches in the thunk have no upstream branch \+        \set. This means we don't know to check whether all your work is \+        \saved. The offending branches are:"+      , ""+      , T.unwords untrackedBranches+      , ""+      , "To fix this, you probably want to do:"+      , ""+      ] +++      ((\branch -> "git push -u origin " <> branch) <$> untrackedBranches) +++      [ ""+      , "These will push the branches to the default remote under the same \+        \name, and (thanks to the `-u`) remember that choice so you don't \+        \get this error again."+      ]++    -- loosely by https://stackoverflow.com/questions/7773939/show-git-ahead-and-behind-info-for-all-branches-including-remotes+    stats <- ifor headUpstream $ \branch (upstream, _remote) -> do+      (stat :: [Text]) <- T.lines <$> readGitProcess thunkDir+        [ "rev-list", "--left-right"+        , T.unpack branch <> "..." <> T.unpack upstream+        ]+      let ahead = length $ [ () | Just ('<', _) <- T.uncons <$> stat ]+          behind = length $ [ () | Just ('>', _) <- T.uncons <$> stat ]+      pure (upstream, (ahead, behind))++    -- Those branches which have commits ahead of, i.e. not on, the upstream+    -- branch. Purely being behind is fine.+    let nonGood = Map.filter ((/= 0) . fst . snd) stats++    when (not $ Map.null nonGood) $ failWith $ T.unlines $ mconcat+      [ [ "thunk pack: Certain branches in the thunk have commits not yet pushed upstream:"+        , ""+        ]+      , [ "  " <> branch <> " ahead: " <> T.pack (show ahead) <> " behind: " <> T.pack (show behind) <> " remote branch " <> upstream+        | (branch, (upstream, (ahead, behind))) <- Map.toList nonGood+        ]+      , [ ""+        , "Please push these upstream and try again. (Or just fetch, if they are somehow \+          \pushed but this repo's remote tracking branches don't know it.)"+        ]+      ]++  when checkClean $ do+    -- We assume it's safe to pack the thunk at this point+    putLog Informational "All changes safe in git remotes. OK to pack thunk."++  let remote = maybe "origin" snd $ flip Map.lookup headUpstream =<< mCurrentBranch++  [remoteUri'] <- T.lines <$> readGitProcess thunkDir+    [ "config"+    , "--get"+    , "remote." <> T.unpack remote <> ".url"+    ]++  remoteUri <- case parseGitUri remoteUri' of+    Nothing -> failWith $ "Could not identify git remote: " <> remoteUri'+    Just uri -> pure uri+  (, isWorktree) <$> uriThunkPtr remoteUri mPrivate mCurrentBranch mCurrentCommit++-- | Get the latest revision available from the given source+getLatestRev :: MonadNixThunk m => ThunkSource -> m ThunkRev+getLatestRev os = do+  let gitS = thunkSourceToGitSource os+  (_, commit) <- gitGetCommitBranch (_gitSource_url gitS) (untagName <$> _gitSource_branch gitS)+  getThunkRev os commit++-- | Convert a URI to a thunk+--+-- If the URL is a github URL, we try to just download an archive for+-- performance. If that doesn't work (e.g. authentication issue), we fall back+-- on just doing things the normal way for git repos in general, and save it as+-- a regular git thunk.+uriThunkPtr :: MonadNixThunk m => GitUri -> Maybe Bool -> Maybe Text -> Maybe Text -> m ThunkPtr+uriThunkPtr uri mPrivate mbranch mcommit = do+  commit <- case mcommit of+    Nothing -> snd <$> gitGetCommitBranch uri mbranch+    (Just c) -> return c+  (src, rev) <- uriToThunkSource uri mPrivate mbranch >>= \case+    ThunkSource_GitHub s -> do+      rev <- runExceptT $ githubThunkRev s commit+      case rev of+        Right r -> pure (ThunkSource_GitHub s, r)+        Left e -> do+          putLog Warning "\+\Failed to fetch archive from GitHub. This is probably a private repo. \+\Falling back on normal fetchgit. Original failure:"+          putLog Warning $ prettyNixThunkError e+          let s' = forgetGithub True s+          (,) (ThunkSource_Git s') <$> gitThunkRev s' commit+    ThunkSource_Git s -> (,) (ThunkSource_Git s) <$> gitThunkRev s commit+  pure $ ThunkPtr+    { _thunkPtr_rev = rev+    , _thunkPtr_source = src+    }++-- | Convert a 'ThunkCreateSource` to a 'ThunkPtr'.+thunkCreateSourcePtr+  :: MonadNixThunk m+  => ThunkCreateSource  -- ^ Where is the repository?+  -> Maybe Bool         -- ^ Is it private?+  -> Maybe Text         -- ^ Shall we fetch a specific branch?+  -> Maybe Text         -- ^ Shall we check out a specific commit?+  -> m ThunkPtr+thunkCreateSourcePtr source mPriv mBranch mCommit = do+  uri <- case source of+    ThunkCreateSource_Absolute uri -> pure uri+    ThunkCreateSource_Relative dir -> do+      isdir <- liftIO $ doesDirectoryExist dir+      if isdir+        then do+          absolute <- liftIO $ makeAbsolute dir+          pure $ fromMaybe (error "parsing a file:// URI should never fail") $+            parseGitUri ("file://" <> T.pack absolute)+        else failWith $ "Path does not refer to a directory: " <> T.pack dir+  uriThunkPtr uri mPriv mBranch mCommit++-- | N.B. Cannot infer all fields.+--+-- If the thunk is a GitHub thunk and fails, we do *not* fall back like with+-- `uriThunkPtr`. Unlike a plain URL, a thunk src explicitly states which method+-- should be employed, and so we respect that.+uriToThunkSource :: MonadNixThunk m => GitUri -> Maybe Bool -> Maybe Text -> m ThunkSource+uriToThunkSource (GitUri u) mPrivate+  | Right uriAuth <- URI.uriAuthority u+  , Just scheme <- URI.unRText <$> URI.uriScheme u+  , case scheme of+      "ssh" -> uriAuth == URI.Authority+        { URI.authUserInfo = Just $ URI.UserInfo (fromRight' $ URI.mkUsername "git") Nothing+        , URI.authHost = fromRight' $ URI.mkHost "github.com"+        , URI.authPort = Nothing+        }+      s -> s `L.elem` [ "git", "https", "http" ] -- "http:" just redirects to "https:"+        && URI.unRText (URI.authHost uriAuth) == "github.com"+  , Just (_, owner :| [repoish]) <- URI.uriPath u+  = \mbranch -> do+      isPrivate <- getIsPrivate+      pure $ ThunkSource_GitHub $ GitHubSource+        { _gitHubSource_owner = N $ URI.unRText owner+        , _gitHubSource_repo = N $ let+            repoish' = URI.unRText repoish+          in fromMaybe repoish' $ T.stripSuffix ".git" repoish'+        , _gitHubSource_branch = N <$> mbranch+        , _gitHubSource_private = isPrivate+        }++  | otherwise = \mbranch -> do+      isPrivate <- getIsPrivate+      pure $ ThunkSource_Git $ GitSource+        { _gitSource_url = GitUri u+        , _gitSource_branch = N <$> mbranch+        , _gitSource_fetchSubmodules = False -- TODO: How do we determine if this should be true?+        , _gitSource_private = isPrivate+        }+  where+    getIsPrivate = maybe (guessGitRepoIsPrivate $ GitUri u) pure mPrivate++guessGitRepoIsPrivate :: MonadNixThunk m => GitUri -> m Bool+guessGitRepoIsPrivate uri = flip fix urisToTry $ \loop -> \case+  [] -> pure True+  uriAttempt:xs -> do+    result <- readCreateProcessWithExitCode $+      isolateGitProc $+        gitProcNoRepo+          [ "ls-remote"+          , "--quiet"+          , "--exit-code"+          , "--symref"+          , T.unpack $ gitUriToText uriAttempt+          ]+    case result of+      (ExitSuccess, _, _) -> pure False -- Must be a public repo+      _ -> loop xs+  where+    urisToTry = nubOrd $+      -- Include the original URI if it isn't using SSH because SSH will certainly fail.+      [uri | fmap URI.unRText (URI.uriScheme (unGitUri uri)) /= Just "ssh"] <>+      [changeScheme "https" uri, changeScheme "http" uri]+    changeScheme scheme (GitUri u) = GitUri $ u+      { URI.uriScheme = URI.mkScheme scheme+      , URI.uriAuthority = (\x -> x { URI.authUserInfo = Nothing }) <$> URI.uriAuthority u+      }++getThunkRev+  :: forall m+  .  MonadNixThunk m+  => ThunkSource+  -> Text+  -> m ThunkRev+getThunkRev os commit = case os of+  ThunkSource_GitHub s -> githubThunkRev s commit+  ThunkSource_Git s -> gitThunkRev s commit++-- Funny signature indicates no effects depend on the optional branch name.+githubThunkRev+  :: forall m+  .  MonadNixThunk m+  => GitHubSource+  -> Text+  -> m ThunkRev+githubThunkRev s commit = do+  owner <- forcePP $ _gitHubSource_owner s+  repo <- forcePP $ _gitHubSource_repo s+  revTarball <- URI.mkPathPiece $ commit <> ".tar.gz"+  let archiveUri = GitUri $ URI.URI+        { URI.uriScheme = Just $ fromRight' $ URI.mkScheme "https"+        , URI.uriAuthority = Right $ URI.Authority+          { URI.authUserInfo = Nothing+          , URI.authHost = fromRight' $ URI.mkHost "github.com"+          , URI.authPort = Nothing+          }+        , URI.uriPath = Just ( False+                         , owner :| [ repo, fromRight' $ URI.mkPathPiece "archive", revTarball ]+                     )+    , URI.uriQuery = []+    , URI.uriFragment = Nothing+    }+  hash <- getNixSha256ForUriUnpacked archiveUri+  putLog Debug $ "Nix sha256 is " <> hash+  return $ ThunkRev+    { _thunkRev_commit = commitNameToRef $ N commit+    , _thunkRev_nixSha256 = hash+    }+  where+    forcePP :: Name entity -> m (URI.RText 'URI.PathPiece)+    forcePP = URI.mkPathPiece . untagName++gitThunkRev+  :: MonadNixThunk m+  => GitSource+  -> Text+  -> m ThunkRev+gitThunkRev s commit = do+  let u = _gitSource_url s+      protocols = ["file", "https", "ssh", "git"]+      scheme = maybe "file" URI.unRText $ URI.uriScheme $ (\(GitUri x) -> x) u+  unless (T.toLower scheme `elem` protocols) $+    failWith $ "obelisk currently only supports "+      <> T.intercalate ", " protocols <> " protocols for plain Git remotes"+  hash <- nixPrefetchGit u commit $ _gitSource_fetchSubmodules s+  putLog Informational $ "Nix sha256 is " <> hash+  pure $ ThunkRev+    { _thunkRev_commit = commitNameToRef (N commit)+    , _thunkRev_nixSha256 = hash+    }++-- | Given the URI to a git remote, and an optional branch name, return the name+-- of the branch along with the hash of the commit at tip of that branch.+--+-- If the branch name is passed in, it is returned exactly as-is. If it is not+-- passed it, the default branch of the repo is used instead.++gitGetCommitBranch+  :: MonadNixThunk m => GitUri -> Maybe Text -> m (Text, CommitId)+gitGetCommitBranch uri mbranch = withExitFailMessage ("Failure for git remote " <> uriMsg) $ do+  (_, bothMaps) <- gitLsRemote+    (T.unpack $ gitUriToText uri)+    (GitRef_Branch <$> mbranch)+    Nothing+  branch <- case mbranch of+    Nothing -> withExitFailMessage "Failed to find default branch" $ do+      b <- rethrowE $ gitLookupDefaultBranch bothMaps+      putLog Debug $ "Default branch for remote repo " <> uriMsg <> " is " <> b+      pure b+    Just b -> pure b+  commit <- rethrowE $ gitLookupCommitForRef bothMaps (GitRef_Branch branch)+  putLog Informational $ "Latest commit in branch " <> branch+    <> " from remote repo " <> uriMsg+    <> " is " <> commit+  pure (branch, commit)+  where+    rethrowE = either failWith pure+    uriMsg = gitUriToText uri++parseGitUri :: Text -> Maybe GitUri+parseGitUri x = GitUri <$> (parseFileURI x <|> parseAbsoluteURI x <|> parseSshShorthand x)++parseFileURI :: Text -> Maybe URI.URI+parseFileURI uri = if "/" `T.isPrefixOf` uri then parseAbsoluteURI ("file://" <> uri) else Nothing++parseAbsoluteURI :: Text -> Maybe URI.URI+parseAbsoluteURI uri = do+  parsedUri <- URI.mkURI uri+  guard $ URI.isPathAbsolute parsedUri+  pure parsedUri++parseSshShorthand :: Text -> Maybe URI.URI+parseSshShorthand uri = do+  -- This is what git does to check that the remote+  -- is not a local file path when parsing shorthand.+  -- Last referenced from here:+  -- https://github.com/git/git/blob/95ec6b1b3393eb6e26da40c565520a8db9796e9f/connect.c#L712+  let+    (authAndHostname, colonAndPath) = T.break (== ':') uri+    properUri = "ssh://" <> authAndHostname <> "/" <> T.drop 1 colonAndPath+  -- Shorthand is valid iff a colon is present and it occurs before the first slash+  -- This check is used to disambiguate a filepath containing a colon from shorthand+  guard $ isNothing (T.findIndex (=='/') authAndHostname)+        && not (T.null colonAndPath)+  URI.mkURI properUri++-- The following code has been adapted from the 'Data.Git.Ref',+-- which is apparently no longer maintained++-- | Represent a git reference (SHA1)+newtype Ref hash = Ref { unRef :: Digest hash }+  deriving (Eq, Ord, Typeable)++-- | Invalid Reference exception raised when+-- using something that is not a ref as a ref.+newtype RefInvalid = RefInvalid { unRefInvalid :: ByteString }+  deriving (Show, Eq, Data, Typeable)++instance Exception RefInvalid++refFromHexString :: HashAlgorithm hash => String -> Ref hash+refFromHexString = refFromHex . BSC.pack++refFromHex :: HashAlgorithm hash => BSC.ByteString -> Ref hash+refFromHex s =+  case convertFromBase Base16 s :: Either String ByteString of+    Left _ -> throw $ RefInvalid s+    Right h -> case digestFromByteString h of+      Nothing -> throw $ RefInvalid s+      Just d -> Ref d++-- | transform a ref into an hexadecimal string+refToHexString :: Ref hash -> String+refToHexString (Ref d) = show d++instance Show (Ref hash) where+  show (Ref bs) = BSC.unpack $ convertToBase Base16 bs