diff --git a/Annex/Content.hs b/Annex/Content.hs
--- a/Annex/Content.hs
+++ b/Annex/Content.hs
@@ -1,6 +1,6 @@
 {- git-annex file content managing
  -
- - Copyright 2010-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2010-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -36,6 +36,7 @@
 	linkOrCopy',
 	sendAnnex,
 	prepSendAnnex,
+	prepSendAnnex',
 	removeAnnex,
 	moveBad,
 	KeyLocation(..),
@@ -446,14 +447,15 @@
  - The rollback action should remove the data that was transferred.
  -}
 sendAnnex :: Key -> Annex () -> (FilePath -> Annex a) -> Annex a
-sendAnnex key rollback sendobject = go =<< prepSendAnnex key
+sendAnnex key rollback sendobject = go =<< prepSendAnnex' key
   where
-	go (Just (f, checksuccess)) = do
+	go (Just (f, check)) = do
 		r <- sendobject f
-		unlessM checksuccess $ do
-			rollback
-			giveup "content changed while it was being sent"
-		return r
+		check >>= \case
+			Nothing -> return r
+			Just err -> do
+				rollback
+				giveup err
 	go Nothing = giveup "content not available to send"
 
 {- Returns a file that contains an object's content,
@@ -482,6 +484,16 @@
 	return $ if null cache'
 		then Nothing
 		else Just (fromRawFilePath f, sameInodeCache f cache')
+
+prepSendAnnex' :: Key -> Annex (Maybe (FilePath, Annex (Maybe String)))
+prepSendAnnex' key = prepSendAnnex key >>= \case
+	Just (f, checksuccess) -> 
+		let checksuccess' = ifM checksuccess
+			( return Nothing
+			, return (Just "content changed while it was being sent")
+			)
+		in return (Just (f, checksuccess'))
+	Nothing -> return Nothing
 
 cleanObjectLoc :: Key -> Annex () -> Annex ()
 cleanObjectLoc key cleaner = do
diff --git a/Annex/CopyFile.hs b/Annex/CopyFile.hs
--- a/Annex/CopyFile.hs
+++ b/Annex/CopyFile.hs
@@ -113,7 +113,9 @@
 			( case iv of
 				Just x -> ifM (liftIO $ finalizeIncremental x)
 					( return (True, Verified)
-					, return (False, UnVerified)
+					, do
+						warning "verification of content failed"
+						return (False, UnVerified)
 					)
 				Nothing -> return (True, UnVerified)
 			, return (False, UnVerified)
diff --git a/Annex/Drop.hs b/Annex/Drop.hs
--- a/Annex/Drop.hs
+++ b/Annex/Drop.hs
@@ -10,7 +10,6 @@
 module Annex.Drop where
 
 import Annex.Common
-import qualified Annex
 import Logs.Trust
 import Annex.NumCopies
 import Types.Remote (uuid, appendonly, config, remotetype, thirdPartyPopulated)
@@ -119,10 +118,10 @@
 
 	dropl fs n = checkdrop fs n Nothing $ \pcc numcopies mincopies ->
 		stopUnless (inAnnex key) $
-			Command.Drop.startLocal pcc afile ai si numcopies mincopies key preverified
+			Command.Drop.startLocal pcc afile ai si numcopies mincopies key preverified (Command.Drop.DroppingUnused False)
 
 	dropr fs r n  = checkdrop fs n (Just $ Remote.uuid r) $ \pcc numcopies mincopies ->
-		Command.Drop.startRemote pcc afile ai si numcopies mincopies key r
+		Command.Drop.startRemote pcc afile ai si numcopies mincopies key (Command.Drop.DroppingUnused False) r
 
 	ai = mkActionItem (key, afile)
 
diff --git a/Annex/Init.hs b/Annex/Init.hs
--- a/Annex/Init.hs
+++ b/Annex/Init.hs
@@ -1,6 +1,6 @@
 {- git-annex repository initialization
  -
- - Copyright 2011-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -51,14 +51,15 @@
 import Utility.UserInfo
 import qualified Utility.RawFilePath as R
 import Utility.ThreadScheduler
-#ifndef mingw32_HOST_OS
 import Annex.Perms
+#ifndef mingw32_HOST_OS
 import Utility.FileMode
 import System.Posix.User
 import qualified Utility.LockFile.Posix as Posix
 #endif
 
 import qualified Data.Map as M
+import Control.Monad.IO.Class (MonadIO)
 #ifndef mingw32_HOST_OS
 import Data.Either
 import qualified System.FilePath.ByteString as P
@@ -241,32 +242,40 @@
  - or removing write access from files. -}
 probeCrippledFileSystem :: Annex Bool
 probeCrippledFileSystem = withEventuallyCleanedOtherTmp $ \tmp -> do
-	(r, warnings) <- liftIO $ probeCrippledFileSystem' tmp
+	(r, warnings) <- probeCrippledFileSystem' tmp
+		(Just freezeContent)
+		(Just thawContent)
 	mapM_ warning warnings
 	return r
 
-probeCrippledFileSystem' :: RawFilePath -> IO (Bool, [String])
+probeCrippledFileSystem'
+	:: (MonadIO m, MonadCatch m)
+	=> RawFilePath
+	-> Maybe (RawFilePath -> m ())
+	-> Maybe (RawFilePath -> m ())
+	-> m (Bool, [String])
 #ifdef mingw32_HOST_OS
-probeCrippledFileSystem' _ = return (True, [])
+probeCrippledFileSystem' _ _ _ = return (True, [])
 #else
-probeCrippledFileSystem' tmp = do
-	let f = fromRawFilePath (tmp P.</> "gaprobe")
-	writeFile f ""
-	r <- probe f
-	void $ tryIO $ allowWrite (toRawFilePath f)
-	removeFile f
+probeCrippledFileSystem' tmp freezecontent thawcontent = do
+	let f = tmp P.</> "gaprobe"
+	let f' = fromRawFilePath f
+	liftIO $ writeFile f' ""
+	r <- probe f'
+	void $ tryNonAsync $ (fromMaybe (liftIO . allowWrite) thawcontent) f
+	liftIO $ removeFile f'
 	return r
   where
 	probe f = catchDefaultIO (True, []) $ do
 		let f2 = f ++ "2"
-		removeWhenExistsWith R.removeLink (toRawFilePath f2)
-		createSymbolicLink f f2
-		removeWhenExistsWith R.removeLink (toRawFilePath f2)
-		preventWrite (toRawFilePath f)
+		liftIO $ removeWhenExistsWith R.removeLink (toRawFilePath f2)
+		liftIO $ createSymbolicLink f f2
+		liftIO $ removeWhenExistsWith R.removeLink (toRawFilePath f2)
+		(fromMaybe (liftIO . preventWrite) freezecontent) (toRawFilePath f)
 		-- Should be unable to write to the file, unless
 		-- running as root, but some crippled
 		-- filesystems ignore write bit removals.
-		ifM ((== 0) <$> getRealUserID)
+		liftIO $ ifM ((== 0) <$> getRealUserID)
 			( return (False, [])
 			, do
 				r <- catchBoolIO $ do
@@ -283,7 +292,8 @@
 	warning "Detected a crippled filesystem."
 	setCrippledFileSystem True
 
-	{- Normally git disables core.symlinks itself when the
+	{- Normally git disables core.symlinks itself when the:w
+	 -
 	 - filesystem does not support them. But, even if symlinks are
 	 - supported, we don't use them by default in a crippled
 	 - filesystem. -}
diff --git a/Annex/Perms.hs b/Annex/Perms.hs
--- a/Annex/Perms.hs
+++ b/Annex/Perms.hs
@@ -1,6 +1,6 @@
 {- git-annex file permissions
  -
- - Copyright 2012-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2012-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -17,7 +17,6 @@
 	freezeContent,
 	isContentWritePermOk,
 	thawContent,
-	chmodContent,
 	createContentDir,
 	freezeContentDir,
 	thawContentDir,
@@ -132,8 +131,9 @@
  - owned by another user, so failure to set this mode is ignored.
  -}
 freezeContent :: RawFilePath -> Annex ()
-freezeContent file = unlessM crippledFileSystem $
+freezeContent file = unlessM crippledFileSystem $ do
 	withShared go
+	freezeHook file
   where
 	go GroupShared = liftIO $ void $ tryIO $ modifyFileMode file $
 		addModes [ownerReadMode, groupReadMode, ownerWriteMode, groupWriteMode]
@@ -157,22 +157,10 @@
 			Nothing -> True
 			Just havemode -> havemode == combineModes (havemode:wantmode)
 
-{- Adjusts read mode of annexed file per core.sharedRepository setting. -}
-chmodContent :: RawFilePath -> Annex ()
-chmodContent file = unlessM crippledFileSystem $
-	withShared go
-  where
-	go GroupShared = liftIO $ void $ tryIO $ modifyFileMode file $
-		addModes [ownerReadMode, groupReadMode]
-	go AllShared = liftIO $ void $ tryIO $ modifyFileMode file $
-		addModes readModes
-	go _ = liftIO $ modifyFileMode file $
-		addModes [ownerReadMode]
-
 {- Allows writing to an annexed file that freezeContent was called on
  - before. -}
 thawContent :: RawFilePath -> Annex ()
-thawContent file = thawPerms $ withShared go
+thawContent file = thawPerms (withShared go) (thawHook file)
   where
 	go GroupShared = liftIO $ void $ tryIO $ groupWriteRead file
 	go AllShared = liftIO $ void $ tryIO $ groupWriteRead file
@@ -180,11 +168,12 @@
 
 {- Runs an action that thaws a file's permissions. This will probably
  - fail on a crippled filesystem. But, if file modes are supported on a
- - crippled filesystem, the file may be frozen, so try to thaw it. -}
-thawPerms :: Annex () -> Annex ()
-thawPerms a = ifM crippledFileSystem
-	( void $ tryNonAsync a
-	, a
+ - crippled filesystem, the file may be frozen, so try to thaw its
+ - permissions. -}
+thawPerms :: Annex () -> Annex () -> Annex ()
+thawPerms a hook = ifM crippledFileSystem
+	( void (tryNonAsync a)
+	, hook >> a
 	)
 
 {- Blocks writing to the directory an annexed file is in, to prevent the
@@ -193,8 +182,9 @@
  - file.
  -}
 freezeContentDir :: RawFilePath -> Annex ()
-freezeContentDir file = unlessM crippledFileSystem $
+freezeContentDir file = unlessM crippledFileSystem $ do
 	withShared go
+	freezeHook dir
   where
 	dir = parentDir file
 	go GroupShared = liftIO $ void $ tryIO $ groupWriteRead dir
@@ -202,8 +192,9 @@
 	go _ = liftIO $ preventWrite dir
 
 thawContentDir :: RawFilePath -> Annex ()
-thawContentDir file = 
-	thawPerms $ liftIO $ allowWrite $ parentDir file
+thawContentDir file = thawPerms (liftIO $ allowWrite dir) (thawHook dir)
+  where
+	dir = parentDir file
 
 {- Makes the directory tree to store an annexed file's content,
  - with appropriate permissions on each level. -}
@@ -212,7 +203,8 @@
 	unlessM (liftIO $ R.doesPathExist dir) $
 		createAnnexDirectory dir 
 	-- might have already existed with restricted perms
-	unlessM crippledFileSystem $
+	unlessM crippledFileSystem $ do
+		thawHook dir
 		liftIO $ allowWrite dir
   where
 	dir = parentDir dest
@@ -226,3 +218,17 @@
 	v <- tryNonAsync a
 	freezeContentDir f
 	either throwM return v
+
+freezeHook :: RawFilePath -> Annex ()
+freezeHook p = maybe noop go =<< annexFreezeContentCommand <$> Annex.getGitConfig
+  where
+	go basecmd = void $ liftIO $
+		boolSystem "sh" [Param "-c", Param $ gencmd basecmd]
+	gencmd = massReplace [ ("%path", shellEscape (fromRawFilePath p)) ]
+
+thawHook :: RawFilePath -> Annex ()
+thawHook p = maybe noop go =<< annexThawContentCommand <$> Annex.getGitConfig
+  where
+	go basecmd = void $ liftIO $
+		boolSystem "sh" [Param "-c", Param $ gencmd basecmd]
+	gencmd = massReplace [ ("%path", shellEscape (fromRawFilePath p)) ]
diff --git a/Annex/Transfer.hs b/Annex/Transfer.hs
--- a/Annex/Transfer.hs
+++ b/Annex/Transfer.hs
@@ -205,13 +205,8 @@
 				, return observeFailure
 				)
 
-	getbytescomplete metervar
-		| transferDirection t == Upload =
-			liftIO $ maybe 0 fromBytesProcessed 
-				<$> readTVarIO metervar
-		| otherwise = do
-			f <- fromRepo $ gitAnnexTmpObjectLocation (transferKey t)
-			liftIO $ catchDefaultIO 0 $ getFileSize f
+	getbytescomplete metervar = liftIO $
+		maybe 0 fromBytesProcessed <$> readTVarIO metervar
 
 detectStallsAndSuggestConfig :: Maybe StallDetection -> TVar (Maybe BytesProcessed) -> Annex a -> Annex a
 detectStallsAndSuggestConfig Nothing _ a = a
diff --git a/Annex/TransferrerPool.hs b/Annex/TransferrerPool.hs
--- a/Annex/TransferrerPool.hs
+++ b/Annex/TransferrerPool.hs
@@ -133,12 +133,8 @@
 	ifM (catchBoolIO $ bracket setup cleanup (go bpv))
 		( return (Right ())
 		, do
-			n <- case transferDirection t of
-				Upload -> liftIO $ atomically $ 
-					fromBytesProcessed <$> readTVar bpv
-				Download -> do
-					f <- runannex $ fromRepo $ gitAnnexTmpObjectLocation (transferKey t)
-					liftIO $ catchDefaultIO 0 $ getFileSize f
+			n <- liftIO $ atomically $
+				fromBytesProcessed <$> readTVar bpv
 			return $ Left $ info { bytesComplete = Just n }
 		)
   where
diff --git a/Build/Configure.hs b/Build/Configure.hs
--- a/Build/Configure.hs
+++ b/Build/Configure.hs
@@ -1,6 +1,7 @@
 {- Checks system configuration and generates Build/SysConfig and Build/Version. -}
 
 {-# OPTIONS_GHC -fno-warn-tabs #-}
+{-# LANGUAGE CPP #-}
 
 module Build.Configure where
 
@@ -23,7 +24,7 @@
 	, testCp "cp_a" "-a"
 	, testCp "cp_p" "-p"
 	, testCp "cp_preserve_timestamps" "--preserve=timestamps"
-	, testCp "cp_reflink_supported" "--reflink=auto"
+	, testCpReflinkAuto
 	, TestCase "xargs -0" $ testCmd "xargs_0" "xargs -0 </dev/null"
 	, TestCase "rsync" $ testCmd "rsync" "rsync --version >/dev/null"
 	, TestCase "curl" $ testCmd "curl" "curl --version >/dev/null"
@@ -50,6 +51,16 @@
   where
 	cmd = "cp " ++ option
 	cmdline = cmd ++ " " ++ testFile ++ " " ++ testFile ++ ".new"
+
+testCpReflinkAuto :: TestCase
+#ifdef mingw32_HOST_OS
+-- Windows does not support reflink so don't even try to use the option.
+testCpReflinkAuto = TestCase k (Config k (BoolConfig False))
+#else
+testCpReflinkAuto = testCp k "--reflink=auto"
+#endif
+  where
+	k = "cp_reflink_supported"
 
 getUpgradeLocation :: Test
 getUpgradeLocation = do
diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,27 @@
+git-annex (8.20210630) upstream; urgency=medium
+
+  * Fixed bug that interrupting git-annex repair (or assistant) while
+    it was fixing repository corruption would lose objects that were
+    contained in pack files. Also the assistant might sometimes have
+    crashed with the same result.
+  * repair: Fix reversion in version 8.20200522 that prevented fetching
+    missing objects from remotes.
+  * sync: Partly work around github behavior that first branch to be pushed
+    to a new repository is assumed to be the head branch, by not pushing
+    synced/git-annex first.
+  * Added annex.freezecontent-command and annex.thawcontent-command
+    configs.
+  * Improve display of errors when transfers fail.
+  * Dropping an unused object with drop --unused or dropunused will
+    mark it as dead, preventing fsck --all from complaining about it
+    after it's been dropped from all repositories.
+  * addurl, importfeed: Added --no-raw option that forces download
+    with youtube-dl or a special remote. In particular this can avoid
+    falling back to raw download when youtube-dl is blocked for some
+    reason.
+
+ -- Joey Hess <id@joeyh.name>  Wed, 30 Jun 2021 11:48:16 -0400
+
 git-annex (8.20210621) upstream; urgency=medium
 
   * New matching options --excludesamecontent and --includesamecontent
diff --git a/Command/AddUrl.hs b/Command/AddUrl.hs
--- a/Command/AddUrl.hs
+++ b/Command/AddUrl.hs
@@ -1,6 +1,6 @@
 {- git-annex command
  -
- - Copyright 2011-2020 Joey Hess <id@joeyh.name>
+ - Copyright 2011-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -54,6 +54,7 @@
 data DownloadOptions = DownloadOptions
 	{ relaxedOption :: Bool
 	, rawOption :: Bool
+	, noRawOption :: Bool
 	, fileOption :: Maybe FilePath
 	, preserveFilenameOption :: Bool
 	, checkGitIgnoreOption :: CheckGitIgnore
@@ -91,6 +92,10 @@
 		( long "raw"
 		<> help "disable special handling for torrents, youtube-dl, etc"
 		)
+	<*> switch
+		( long "no-raw"
+		<> help "prevent downloading raw url content, must use special handling"
+		)
 	<*> (if withfileoptions
 		then optional (strOption
 			( long "file" <> metavar paramFile
@@ -265,7 +270,7 @@
 	addurl = addUrlChecked o url file webUUID $ \k ->
 		ifM (pure (not (rawOption (downloadOptions o))) <&&> youtubeDlSupported url)
 			( return (True, True, setDownloader url YoutubeDownloader)
-			, return (Url.urlExists urlinfo, Url.urlSize urlinfo == fromKey keySize k, url)
+			, checkRaw (downloadOptions o) $ return (Url.urlExists urlinfo, Url.urlSize urlinfo == fromKey keySize k, url)
 			)
 
 {- Check that the url exists, and has the same size as the key,
@@ -326,7 +331,7 @@
 			in ifAnnexed f
 				(alreadyannexed (fromRawFilePath f))
 				(dl f)
-		Left _ -> normalfinish tmp
+		Left _ -> checkRaw o (normalfinish tmp)
 	  where
 		dl dest = withTmpWorkDir mediakey $ \workdir -> do
 			let cleanuptmp = pruneTmpWorkDirBefore tmp (liftIO . removeWhenExistsWith R.removeLink)
@@ -340,7 +345,7 @@
 								showDestinationFile (fromRawFilePath dest)
 								addWorkTree canadd addunlockedmatcher webUUID mediaurl dest mediakey (Just (toRawFilePath mediafile))
 								return $ Just mediakey
-						Right Nothing -> normalfinish tmp
+						Right Nothing -> checkRaw o (normalfinish tmp)
 						Left msg -> do
 							cleanuptmp
 							warning msg
@@ -356,6 +361,11 @@
 				else do
 					warning $ dest ++ " already exists; not overwriting"
 					return Nothing
+	
+checkRaw :: DownloadOptions -> Annex a -> Annex a
+checkRaw o a
+	| noRawOption o = giveup "Unable to use youtube-dl or a special remote and --no-raw was specified."
+	| otherwise = a
 
 {- The destination file is not known at start time unless the user provided
  - a filename. It's not displayed then for output consistency, 
@@ -464,8 +474,9 @@
 nodownloadWeb addunlockedmatcher o url urlinfo file
 	| Url.urlExists urlinfo = if rawOption o
 		then nomedia
-		else either (const nomedia) (usemedia . toRawFilePath)
-			=<< youtubeDlFileName url
+		else youtubeDlFileName url >>= \case
+			Right mediafile -> usemedia (toRawFilePath mediafile)
+			Left _ -> checkRaw o nomedia
 	| otherwise = do
 		warning $ "unable to access url: " ++ url
 		return Nothing
diff --git a/Command/Drop.hs b/Command/Drop.hs
--- a/Command/Drop.hs
+++ b/Command/Drop.hs
@@ -86,29 +86,32 @@
 	checkDropAuto (autoMode o) from afile key $ \numcopies mincopies ->
 		stopUnless wantdrop $
 			case from of
-				Nothing -> startLocal pcc afile ai si numcopies mincopies key []
-				Just remote -> startRemote pcc afile ai si numcopies mincopies key remote
+				Nothing -> startLocal pcc afile ai si numcopies mincopies key [] ud
+				Just remote -> startRemote pcc afile ai si numcopies mincopies key ud remote
   where
 	wantdrop
 		| autoMode o = wantDrop False (Remote.uuid <$> from) (Just key) afile Nothing
 		| otherwise = return True
 	pcc = PreferredContentChecked (autoMode o)
+	ud = case (batchOption o, keyOptions o) of
+		(NoBatch, Just WantUnusedKeys) -> DroppingUnused True
+		_ -> DroppingUnused False
 
 startKeys :: DropOptions -> Maybe Remote -> (SeekInput, Key, ActionItem) -> CommandStart
 startKeys o from (si, key, ai) = start' o from key (AssociatedFile Nothing) ai si
 
-startLocal :: PreferredContentChecked -> AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> MinCopies -> Key -> [VerifiedCopy] -> CommandStart
-startLocal pcc afile ai si numcopies mincopies key preverified =
+startLocal :: PreferredContentChecked -> AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> MinCopies -> Key -> [VerifiedCopy] -> DroppingUnused -> CommandStart
+startLocal pcc afile ai si numcopies mincopies key preverified ud =
 	starting "drop" (OnlyActionOn key ai) si $
-		performLocal pcc key afile numcopies mincopies preverified
+		performLocal pcc key afile numcopies mincopies preverified ud
 
-startRemote :: PreferredContentChecked -> AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> MinCopies -> Key -> Remote -> CommandStart
-startRemote pcc afile ai si numcopies mincopies key remote = 
+startRemote :: PreferredContentChecked -> AssociatedFile -> ActionItem -> SeekInput -> NumCopies -> MinCopies -> Key -> DroppingUnused -> Remote -> CommandStart
+startRemote pcc afile ai si numcopies mincopies key ud remote = 
 	starting ("drop " ++ Remote.name remote) (OnlyActionOn key ai) si $
-		performRemote pcc key afile numcopies mincopies remote
+		performRemote pcc key afile numcopies mincopies remote ud
 
-performLocal :: PreferredContentChecked -> Key -> AssociatedFile -> NumCopies -> MinCopies -> [VerifiedCopy] -> CommandPerform
-performLocal pcc key afile numcopies mincopies preverified = lockContentForRemoval key fallback $ \contentlock -> do
+performLocal :: PreferredContentChecked -> Key -> AssociatedFile -> NumCopies -> MinCopies -> [VerifiedCopy] -> DroppingUnused -> CommandPerform
+performLocal pcc key afile numcopies mincopies preverified ud = lockContentForRemoval key fallback $ \contentlock -> do
 	u <- getUUID
 	(tocheck, verified) <- verifiableCopies key [u]
 	doDrop pcc u (Just contentlock) key afile numcopies mincopies [] (preverified ++ verified) tocheck
@@ -120,7 +123,7 @@
 				]
 			removeAnnex contentlock
 			notifyDrop afile True
-			next $ cleanupLocal key
+			next $ cleanupLocal key ud
 		, do 
 			notifyDrop afile False
 			stop
@@ -131,10 +134,10 @@
 	-- is present, but due to buffering, may find it present for the
 	-- second file before the first is dropped. If so, nothing remains
 	-- to be done except for cleaning up.
-	fallback = next $ cleanupLocal key
+	fallback = next $ cleanupLocal key ud
 
-performRemote :: PreferredContentChecked -> Key -> AssociatedFile -> NumCopies -> MinCopies -> Remote -> CommandPerform
-performRemote pcc key afile numcopies mincopies remote = do
+performRemote :: PreferredContentChecked -> Key -> AssociatedFile -> NumCopies -> MinCopies -> Remote -> DroppingUnused -> CommandPerform
+performRemote pcc key afile numcopies mincopies remote ud = do
 	-- Filter the uuid it's being dropped from out of the lists of
 	-- places assumed to have the key, and places to check.
 	(tocheck, verified) <- verifiableCopies key [uuid]
@@ -147,22 +150,35 @@
 				, show proof
 				]
 			ok <- Remote.action (Remote.removeKey remote key)
-			next $ cleanupRemote key remote ok
+			next $ cleanupRemote key remote ud ok
 		, stop
 		)
   where
 	uuid = Remote.uuid remote
 
-cleanupLocal :: Key -> CommandCleanup
-cleanupLocal key = do
-	logStatus key InfoMissing
+cleanupLocal :: Key -> DroppingUnused -> CommandCleanup
+cleanupLocal key ud = do
+	logStatus key (dropStatus ud)
 	return True
 
-cleanupRemote :: Key -> Remote -> Bool -> CommandCleanup
-cleanupRemote key remote ok = do
+cleanupRemote :: Key -> Remote -> DroppingUnused -> Bool -> CommandCleanup
+cleanupRemote key remote ud ok = do
 	when ok $
-		Remote.logStatus remote key InfoMissing
+		Remote.logStatus remote key (dropStatus ud)
 	return ok
+
+{- Set when the user explicitly chose to operate on unused content.
+ - Presumably the user still expects the last git-annex unused to be
+ - correct at this point. -}
+newtype DroppingUnused = DroppingUnused Bool
+
+{- When explicitly dropping unused content, mark the key as dead, at least
+ - in the repository it was dropped from. It may still be in other
+ - repositories, and will not be treated as dead until dropped from all of
+ - them. -}
+dropStatus :: DroppingUnused -> LogStatus
+dropStatus (DroppingUnused False) = InfoMissing
+dropStatus (DroppingUnused True) = InfoDead
 
 {- Before running the dropaction, checks specified remotes to
  - verify that enough copies of a key exist to allow it to be
diff --git a/Command/DropUnused.hs b/Command/DropUnused.hs
--- a/Command/DropUnused.hs
+++ b/Command/DropUnused.hs
@@ -49,7 +49,7 @@
 perform from numcopies mincopies key = case from of
 	Just r -> do
 		showAction $ "from " ++ Remote.name r
-		Command.Drop.performRemote pcc key (AssociatedFile Nothing) numcopies mincopies r
+		Command.Drop.performRemote pcc key (AssociatedFile Nothing) numcopies mincopies r ud
 	Nothing -> ifM (inAnnex key)
 		( droplocal
 		, ifM (objectFileExists key)
@@ -63,8 +63,9 @@
 			)
 		)
   where
-	droplocal = Command.Drop.performLocal pcc key (AssociatedFile Nothing) numcopies mincopies []
+	droplocal = Command.Drop.performLocal pcc key (AssociatedFile Nothing) numcopies mincopies [] ud
 	pcc = Command.Drop.PreferredContentChecked False
+	ud = Command.Drop.DroppingUnused True
 
 performOther :: (Key -> Git.Repo -> RawFilePath) -> Key -> CommandPerform
 performOther filespec key = do
diff --git a/Command/ImportFeed.hs b/Command/ImportFeed.hs
--- a/Command/ImportFeed.hs
+++ b/Command/ImportFeed.hs
@@ -42,7 +42,7 @@
 import Logs.MetaData
 import Annex.MetaData
 import Annex.FileMatcher
-import Command.AddUrl (addWorkTree)
+import Command.AddUrl (addWorkTree, checkRaw)
 import Annex.UntrustedFilePath
 import qualified Annex.Branch
 import Logs
@@ -185,7 +185,7 @@
 			let f' = fromRawFilePath f
 			r <- Remote.claimingUrl url
 			if Remote.uuid r == webUUID || rawOption (downloadOptions opts)
-				then do
+				then checkRaw (downloadOptions opts) $ do
 					let dlopts = (downloadOptions opts)
 						-- force using the filename
 						-- chosen here
@@ -326,8 +326,9 @@
 			, downloadlink
 			)
 	  where
-		downloadlink = performDownload addunlockedmatcher opts cache todownload
-			{ location = Enclosure linkurl }
+		downloadlink = checkRaw (downloadOptions opts) $
+			performDownload addunlockedmatcher opts cache todownload
+				{ location = Enclosure linkurl }
 
 	addmediafast linkurl mediaurl mediakey =
 		ifM (pure (not (rawOption (downloadOptions opts)))
diff --git a/Command/Mirror.hs b/Command/Mirror.hs
--- a/Command/Mirror.hs
+++ b/Command/Mirror.hs
@@ -69,7 +69,8 @@
 		( Command.Move.toStart Command.Move.RemoveNever afile key ai si =<< getParsed r
 		, do
 			(numcopies, mincopies) <- getSafestNumMinCopies afile key
-			Command.Drop.startRemote pcc afile ai si numcopies mincopies key =<< getParsed r
+			Command.Drop.startRemote pcc afile ai si numcopies mincopies key (Command.Drop.DroppingUnused False)
+				=<< getParsed r
 		)
 	FromRemote r -> checkFailedTransferDirection ai Download $ do
 		haskey <- flip Remote.hasKey key =<< getParsed r
@@ -82,7 +83,7 @@
 			Right False -> ifM (inAnnex key)
 				( do
 					(numcopies, mincopies) <- getSafestNumMinCopies afile key
-					Command.Drop.startLocal pcc afile ai si numcopies mincopies key []
+					Command.Drop.startLocal pcc afile ai si numcopies mincopies key [] (Command.Drop.DroppingUnused False)
 				, stop
 				)
   where
diff --git a/Command/Move.hs b/Command/Move.hs
--- a/Command/Move.hs
+++ b/Command/Move.hs
@@ -186,7 +186,7 @@
 		removeAnnex contentlock
 		next $ do
 			() <- setpresentremote
-			Command.Drop.cleanupLocal key
+			Command.Drop.cleanupLocal key (Command.Drop.DroppingUnused False)
 	faileddrophere setpresentremote = do
 		showLongNote "(Use --force to override this check, or adjust numcopies.)"
 		showLongNote "Content not dropped from here."
@@ -199,7 +199,7 @@
 	-- is present, but due to buffering, may find it present for the
 	-- second file before the first is dropped. If so, nothing remains
 	-- to be done except for cleaning up.
-	lockfailed = next $ Command.Drop.cleanupLocal key
+	lockfailed = next $ Command.Drop.cleanupLocal key (Command.Drop.DroppingUnused False)
 
 fromStart :: RemoveWhen -> AssociatedFile -> Key -> ActionItem -> SeekInput -> Remote -> CommandStart
 fromStart removewhen afile key ai si src = 
@@ -262,7 +262,7 @@
 			, "(" ++ reason ++ ")"
 			]
 		ok <- Remote.action (Remote.removeKey src key)
-		next $ Command.Drop.cleanupRemote key src ok
+		next $ Command.Drop.cleanupRemote key src (Command.Drop.DroppingUnused False) ok
 	
 	faileddropremote = do
 		showLongNote "(Use --force to override this check, or adjust numcopies.)"
diff --git a/Command/Sync.hs b/Command/Sync.hs
--- a/Command/Sync.hs
+++ b/Command/Sync.hs
@@ -604,8 +604,15 @@
  - direct push is tried, with stderr discarded, to update the branch ref
  - on the remote.
  -
- - The sync push forces the update of the remote synced/git-annex branch.
- - This is necessary if a transition has rewritten the git-annex branch.
+ - The sync push first sends the synced/master branch,
+ - and then forces the update of the remote synced/git-annex branch.
+ -
+ - Since some providers like github may treat the first branch sent
+ - as the default branch, it's better to make that be synced/master than
+ - synced/git-annex. (Although neither is ideal, it's the best that
+ - can be managed given the constraints on order.)
+ -
+ - The forcing is necessary if a transition has rewritten the git-annex branch.
  - Normally any changes to the git-annex branch get pulled and merged before
  - this push, so this forcing is unlikely to overwrite new data pushed
  - in from another repository that is also syncing.
@@ -618,8 +625,8 @@
 pushBranch remote mbranch g = directpush `after` annexpush `after` syncpush
   where
 	syncpush = flip Git.Command.runBool g $ pushparams $ catMaybes
-		[ Just $ Git.Branch.forcePush $ refspec Annex.Branch.name
-		, (refspec . fromAdjustedBranch) <$> mbranch
+		[ (refspec . fromAdjustedBranch) <$> mbranch
+		, Just $ Git.Branch.forcePush $ refspec Annex.Branch.name
 		]
 	annexpush = void $ tryIO $ flip Git.Command.runQuiet g $ pushparams
 		[ Git.fromRef $ Git.Ref.base $ Annex.Branch.name ]
diff --git a/Git/Repair.hs b/Git/Repair.hs
--- a/Git/Repair.hs
+++ b/Git/Repair.hs
@@ -1,6 +1,6 @@
 {- git repository recovery
  -
- - Copyright 2013-2014 Joey Hess <id@joeyh.name>
+ - Copyright 2013-2021 Joey Hess <id@joeyh.name>
  -
  - Licensed under the GNU AGPL version 3 or higher.
  -}
@@ -29,6 +29,7 @@
 import Git.Types
 import Git.Fsck
 import Git.Index
+import Git.Env
 import qualified Git.Config as Config
 import qualified Git.Construct as Construct
 import qualified Git.LsTree as LsTree
@@ -61,15 +62,14 @@
 		whenM (isMissing s r) $
 			removeLoose s
 
-{- Explodes all pack files, and deletes them.
- -
- - First moves all pack files to a temp dir, before unpacking them each in
- - turn.
+{- Explodes all pack files to loose objects, and deletes the pack files.
  -
- - This is because unpack-objects will not unpack a pack file if it's in the
- - git repo.
+ - git unpack-objects will not unpack objects from a pack file that are
+ - in the git repo. So, GIT_OBJECT_DIRECTORY is pointed to a temporary
+ - directory, and the loose objects then are moved into place, before
+ - deleting the pack files.
  -
- - Also, this prevents unpack-objects from possibly looking at corrupt
+ - Also, that prevents unpack-objects from possibly looking at corrupt
  - pack files to see if they contain an object, while unpacking a
  - non-corrupt pack file.
  -}
@@ -78,18 +78,28 @@
   where
 	go [] = return False
 	go packs = withTmpDir "packs" $ \tmpdir -> do
+		r' <- addGitEnv r "GIT_OBJECT_DIRECTORY" tmpdir
 		putStrLn "Unpacking all pack files."
 		forM_ packs $ \packfile -> do
-			moveFile packfile (tmpdir </> takeFileName packfile)
-			removeWhenExistsWith R.removeLink
-				(packIdxFile (toRawFilePath packfile))
-		forM_ packs $ \packfile -> do
-			let tmp = tmpdir </> takeFileName packfile
-			allowRead (toRawFilePath tmp)
+			-- Just in case permissions are messed up.
+			allowRead (toRawFilePath packfile)
 			-- May fail, if pack file is corrupt.
 			void $ tryIO $
-				pipeWrite [Param "unpack-objects", Param "-r"] r $ \h ->
-				L.hPut h =<< L.readFile tmp
+				pipeWrite [Param "unpack-objects", Param "-r"] r' $ \h ->
+				L.hPut h =<< L.readFile packfile
+		objs <- dirContentsRecursive tmpdir
+		forM_ objs $ \objfile -> do
+			f <- relPathDirToFile
+				(toRawFilePath tmpdir)
+				(toRawFilePath objfile)
+			let dest = objectsDir r P.</> f
+			createDirectoryIfMissing True
+				(fromRawFilePath (parentDir dest))
+			moveFile objfile (fromRawFilePath dest)
+		forM_ packs $ \packfile -> do
+			let f = toRawFilePath packfile
+			removeWhenExistsWith R.removeLink f
+			removeWhenExistsWith R.removeLink (packIdxFile f)
 		return True
 
 {- Try to retrieve a set of missing objects, from the remotes of a
@@ -106,6 +116,9 @@
 		unlessM (boolSystem "git" [Param "init", File tmpdir]) $
 			error $ "failed to create temp repository in " ++ tmpdir
 		tmpr <- Config.read =<< Construct.fromPath (toRawFilePath tmpdir)
+		let repoconfig r' = fromRawFilePath (localGitDir r' P.</> "config")
+		whenM (doesFileExist (repoconfig r)) $
+			L.readFile (repoconfig r) >>= L.writeFile (repoconfig tmpr)
 		rs <- Construct.fromRemotes r
 		stillmissing <- pullremotes tmpr rs fetchrefstags missing
 		if S.null (knownMissing stillmissing)
diff --git a/Messages/Serialized.hs b/Messages/Serialized.hs
--- a/Messages/Serialized.hs
+++ b/Messages/Serialized.hs
@@ -32,7 +32,7 @@
 	-> (SerializedOutputResponse -> m ())
 	-- ^ Send response to child process.
 	-> (Maybe BytesProcessed -> m ())
-	-- ^ When a progress meter is running, is updated with
+	-- ^ When a progress meter is running, it is updated with
 	-- progress meter values sent by the process.
 	-- When a progress meter is stopped, Nothing is sent.
 	-> (forall a. Annex a -> m a)
diff --git a/Remote/Git.hs b/Remote/Git.hs
--- a/Remote/Git.hs
+++ b/Remote/Git.hs
@@ -549,8 +549,11 @@
 		u <- getUUID
 		hardlink <- wantHardLink
 		-- run copy from perspective of remote
-		onLocalFast st $ Annex.Content.prepSendAnnex key >>= \case
-			Just (object, checksuccess) -> do
+		onLocalFast st $ Annex.Content.prepSendAnnex' key >>= \case
+			Just (object, check) -> do
+				let checksuccess = check >>= \case
+					Just err -> giveup err
+					Nothing -> return True
 				let verify = Annex.Content.RemoteVerify r
 				copier <- mkFileCopier hardlink st
 				(ok, v) <- runTransfer (Transfer Download u (fromKey id key))
@@ -673,7 +676,7 @@
 copyToRemote' repo r st@(State connpool duc _ _ _) key file meterupdate
 	| not $ Git.repoIsUrl repo = ifM duc
 		( guardUsable repo (giveup "cannot access remote") $ commitOnCleanup repo r st $
-			copylocal =<< Annex.Content.prepSendAnnex key
+			copylocal =<< Annex.Content.prepSendAnnex' key
 		, giveup "remote does not have expected annex.uuid value"
 		)
 	| Git.repoIsSsh repo = commitOnCleanup repo r st $
@@ -684,11 +687,11 @@
 	| otherwise = giveup "copying to non-ssh repo not supported"
   where
 	copylocal Nothing = giveup "content not available"
-	copylocal (Just (object, checksuccess)) = do
-		-- The checksuccess action is going to be run in
+	copylocal (Just (object, check)) = do
+		-- The check action is going to be run in
 		-- the remote's Annex, but it needs access to the local
 		-- Annex monad's state.
-		checksuccessio <- Annex.withCurrentState checksuccess
+		checkio <- Annex.withCurrentState check
 		u <- getUUID
 		hardlink <- wantHardLink
 		-- run copy from perspective of remote
@@ -698,9 +701,12 @@
 				let verify = Annex.Content.RemoteVerify r
 				copier <- mkFileCopier hardlink st
 				let rsp = RetrievalAllKeysSecure
+				let checksuccess = liftIO checkio >>= \case
+					Just err -> giveup err
+					Nothing -> return True
 				res <- logStatusAfter key $ Annex.Content.getViaTmp rsp verify key file $ \dest ->
 					metered (Just (combineMeterUpdate meterupdate p)) key $ \_ p' -> 
-						copier object (fromRawFilePath dest) key p' (liftIO checksuccessio) verify
+						copier object (fromRawFilePath dest) key p' checksuccess verify
 				Annex.Content.saveState True
 				return res
 			)
diff --git a/Test.hs b/Test.hs
--- a/Test.hs
+++ b/Test.hs
@@ -142,7 +142,9 @@
 		exitWith exitcode
 	runsubprocesstests (Just _) = isolateGitConfig $ do
 		ensuretmpdir
-		crippledfilesystem <- fst <$> Annex.Init.probeCrippledFileSystem' (toRawFilePath tmpdir)
+		crippledfilesystem <- fst <$> Annex.Init.probeCrippledFileSystem'
+			(toRawFilePath tmpdir)
+			Nothing Nothing
 		adjustedbranchok <- Annex.AdjustedBranch.isGitVersionSupported
 		case tryIngredients ingredients (tastyOptionSet opts) (tests crippledfilesystem adjustedbranchok opts) of
 			Nothing -> error "No tests found!?"
diff --git a/Types/GitConfig.hs b/Types/GitConfig.hs
--- a/Types/GitConfig.hs
+++ b/Types/GitConfig.hs
@@ -104,6 +104,8 @@
 	, annexFsckNudge :: Bool
 	, annexAutoUpgrade :: AutoUpgrade
 	, annexExpireUnused :: Maybe (Maybe Duration)
+	, annexFreezeContentCommand :: Maybe String
+	, annexThawContentCommand :: Maybe String
 	, annexSecureEraseCommand :: Maybe String
 	, annexGenMetaData :: Bool
 	, annexListen :: Maybe String
@@ -191,6 +193,8 @@
 		getmaybe (annexConfig "autoupgrade")
 	, annexExpireUnused = either (const Nothing) Just . parseDuration
 		<$> getmaybe (annexConfig "expireunused")
+	, annexFreezeContentCommand = getmaybe (annexConfig "freezecontent-command")
+	, annexThawContentCommand = getmaybe (annexConfig "thawcontent-command")
 	, annexSecureEraseCommand = getmaybe (annexConfig "secure-erase-command")
 	, annexGenMetaData = getbool (annexConfig "genmetadata") False
 	, annexListen = getmaybe (annexConfig "listen")
diff --git a/doc/git-annex-addurl.mdwn b/doc/git-annex-addurl.mdwn
--- a/doc/git-annex-addurl.mdwn
+++ b/doc/git-annex-addurl.mdwn
@@ -49,6 +49,12 @@
   special remotes. This will for example, make addurl
   download the .torrent file and not the contents it points to.
 
+* `--no-raw`
+
+  Require content pointed to by the url to be downloaded using youtube-dl
+  or a special remote, rather than the raw content of the url. if that
+  cannot be done, the add will fail.
+
 * `--file=name`
 
   Use with a filename that does not yet exist to add a new file
diff --git a/doc/git-annex-dead.mdwn b/doc/git-annex-dead.mdwn
--- a/doc/git-annex-dead.mdwn
+++ b/doc/git-annex-dead.mdwn
@@ -18,7 +18,7 @@
 
 When a key is specified, indicates that the content of that key has been
 irretrievably lost. This prevents commands like `git annex fsck --all`
-from complaining about it; `--all` will not operate on the key anymore.
+from complaining about it. 
 (To undo, add the key's content back to the repository, 
 by using eg, `git-annex reinject`.)
 
diff --git a/doc/git-annex-dropunused.mdwn b/doc/git-annex-dropunused.mdwn
--- a/doc/git-annex-dropunused.mdwn
+++ b/doc/git-annex-dropunused.mdwn
@@ -9,7 +9,7 @@
 # DESCRIPTION
 
 Drops the data corresponding to the numbers, as listed by the last
-git annex unused`
+`git annex unused`
 
 You can also specify ranges of numbers, such as "1-1000".
 Or, specify "all" to drop all unused data.
diff --git a/doc/git-annex-importfeed.mdwn b/doc/git-annex-importfeed.mdwn
--- a/doc/git-annex-importfeed.mdwn
+++ b/doc/git-annex-importfeed.mdwn
@@ -58,6 +58,13 @@
   special remotes. This will for example, make importfeed
   download a .torrent file and not the contents it points to.
 
+* `--no-raw`
+
+  Require content pointed to by the url to be downloaded using youtube-dl
+  or a special remote, rather than the raw content of the url. if that
+  cannot be done, the import will fail, and the next import of the feed
+  will retry.
+
 * `--template`
 
   Controls where the files are stored.
diff --git a/doc/git-annex.mdwn b/doc/git-annex.mdwn
--- a/doc/git-annex.mdwn
+++ b/doc/git-annex.mdwn
@@ -1213,6 +1213,16 @@
 
   For example, to use the wipe command, set it to `wipe -f %file`.
 
+* `annex.freezecontent-command`, `annex.thawcontent-command`
+
+  Usually the write permission bits are unset to protect annexed objects
+  from being modified or deleted. The freezecontent-command is run after
+  git-annex has removed the write bit. The thawcontent-command should undo
+  its effect, and is run before git-annex restores the write bit.
+
+  In the command line, %path is replaced with the file or directory to
+  operate on.
+
 * `annex.tune.objecthash1`, `annex.tune.objecthashlower`, `annex.tune.branchhash1`
 
   These can be passed to `git annex init` to tune the repository.
diff --git a/git-annex.cabal b/git-annex.cabal
--- a/git-annex.cabal
+++ b/git-annex.cabal
@@ -1,5 +1,5 @@
 Name: git-annex
-Version: 8.20210621
+Version: 8.20210630
 Cabal-Version: >= 1.10
 License: AGPL-3
 Maintainer: Joey Hess <id@joeyh.name>