diff --git a/intro.cabal b/intro.cabal
--- a/intro.cabal
+++ b/intro.cabal
@@ -3,7 +3,7 @@
 -- see: https://github.com/sol/hpack
 
 name:           intro
-version:        0.1.0.1
+version:        0.1.0.2
 synopsis:       "Fixed Prelude" - Mostly total and safe, provides Text and Monad transformers
 description:    Modern Prelude which provides safe alternatives for most of the partial functions. Text is preferred over String. Container types and Monad transformers are provided. Most important - this Prelude avoids fanciness. This means it just reexports from base and commonly used libraries and doesn\'t invent its own stuff. Everything is in one file.
 category:       Prelude
diff --git a/src/Intro.hs b/src/Intro.hs
--- a/src/Intro.hs
+++ b/src/Intro.hs
@@ -84,6 +84,7 @@
   , Data.Maybe.Maybe(Nothing, Just)
   , Data.Maybe.catMaybes
   , Data.Maybe.fromMaybe
+  , (?:)
   , Data.Maybe.isJust
   , Data.Maybe.isNothing
   --, Data.Maybe.listToMaybe -- use headMay
@@ -558,6 +559,7 @@
 
   -- * Generic type classes
   , GHC.Generics.Generic
+  , GHC.Generics.Generic1
   , Data.Typeable.Typeable
   , Control.DeepSeq.NFData
   , Data.Binary.Binary
@@ -602,10 +604,9 @@
   , Intro.Trustworthy.traceM
   , Intro.Trustworthy.traceShow
   , Intro.Trustworthy.traceShowM
-  , Intro.Trustworthy.traceStack
-  , Intro.Trustworthy.traceStackM
 ) where
 
+import Data.Maybe (Maybe, fromMaybe)
 import Data.Function ((.), ($))
 import Control.Monad.Trans (MonadIO(liftIO))
 import Data.ByteString (ByteString)
@@ -720,7 +721,7 @@
 
 -- | Parse a string type using the 'Text.Read.Read' instance.
 -- Succeeds if there is exactly one valid result.
-readMaybe :: (Text.Read.Read b, ConvertibleStrings a String) => a -> Data.Maybe.Maybe b
+readMaybe :: (Text.Read.Read b, ConvertibleStrings a String) => a -> Maybe b
 readMaybe = Text.Read.readMaybe . convertString
 {-# INLINE readMaybe #-}
 
@@ -843,6 +844,12 @@
 infixr 8 .:
 {-# INLINE (.:) #-}
 
+-- | An infix form of 'fromMaybe' with arguments flipped.
+(?:) :: Maybe a -> a -> a
+(?:) = Data.Function.flip fromMaybe
+infix 1 ?:
+{-# INLINE (?:) #-}
+
 -- | @()@ lifted to an 'Control.Applicative.Applicative'.
 --
 --   @skip = 'Control.Applicative.pure' ()@
@@ -854,7 +861,7 @@
 -- of a logic error at runtime. Use this function instead of 'Prelude.error'.
 -- A stack trace will be provided.
 --
--- In general, prefer total functions. You can use 'Data.Maybe.Maybe', 'Data.Either.Either',
+-- In general, prefer total functions. You can use 'Maybe', 'Data.Either.Either',
 -- 'Control.Monad.Except.ExceptT' or 'Control.Monad.Except.MonadError' for error handling.
 panic :: HAS_CALL_STACK String -> a
 panic msg = Prelude.error $
diff --git a/src/Intro/Trustworthy.hs b/src/Intro/Trustworthy.hs
--- a/src/Intro/Trustworthy.hs
+++ b/src/Intro/Trustworthy.hs
@@ -28,13 +28,11 @@
   , traceM
   , traceShow
   , traceShowM
-  , traceStack
-  , traceStackM
 ) where
 
-import Control.Applicative (Applicative(pure))
+import Control.Applicative (Applicative)
 import Control.Monad.Trans (MonadIO(liftIO))
-import Data.Function ((.), ($))
+import Data.Function ((.))
 import Data.Text (Text)
 import Text.Show (Show)
 import qualified Data.DList
@@ -82,24 +80,6 @@
 traceM :: APPLICATIVE m => Text -> m ()
 traceM = Debug.Trace.traceM . Data.Text.unpack
 {-# WARNING traceM "'traceM' remains in code" #-}
-
--- | like 'trace', but additionally prints a call stack if one is
--- available.
---
--- In the current GHC implementation, the call stack is only
--- available if the program was compiled with @-prof@; otherwise
--- 'traceStack' behaves exactly like 'trace'.  Entries in the call
--- stack correspond to @SCC@ annotations, so it is a good idea to use
--- @-fprof-auto@ or @-fprof-auto-calls@ to add SCC annotations automatically.
-traceStack :: Text -> a -> a
-traceStack = Debug.Trace.traceStack . Data.Text.unpack
-{-# WARNING traceStack "'traceStack' remains in code" #-}
-
--- | Like 'traceStack' but returning unit in an arbitrary 'Applicative' context. Allows
--- for convenient use in do-notation.
-traceStackM :: APPLICATIVE m => Text -> m ()
-traceStackM s = traceStack s $ pure ()
-{-# WARNING traceStackM "'traceStackM' remains in code" #-}
 
 -- | Like 'trace', but uses 'show' on the argument to convert it to a 'String'.
 --