diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,7 @@
+# 0.7.0.0
+
+* Write trace messages to stderr.
+
 # 0.6.0.0
 
 * Add polymorphic type family `Undefined` that emits a `TypeError`.
diff --git a/incipit-base.cabal b/incipit-base.cabal
--- a/incipit-base.cabal
+++ b/incipit-base.cabal
@@ -1,11 +1,11 @@
 cabal-version: 2.2
 
--- This file has been generated from package.yaml by hpack version 0.36.1.
+-- This file has been generated from package.yaml by hpack version 0.38.3.
 --
 -- see: https://github.com/sol/hpack
 
 name:           incipit-base
-version:        0.6.1.1
+version:        0.7.0.2
 synopsis:       A Prelude for Polysemy – Base Reexports
 description:    See https://hackage.haskell.org/package/incipit-base/docs/IncipitBase.html
 category:       Prelude
@@ -92,8 +92,10 @@
       LiberalTypeSynonyms
       MonadComprehensions
       MultiWayIf
+      NoFieldSelectors
       OverloadedLabels
       OverloadedLists
+      OverloadedRecordDot
       OverloadedStrings
       PackageImports
       PartialTypeSignatures
@@ -109,14 +111,12 @@
       UndecidableInstances
       UnicodeSyntax
       ViewPatterns
-      OverloadedRecordDot
-      NoFieldSelectors
   ghc-options: -Wall -Widentities -Wincomplete-uni-patterns -Wmissing-deriving-strategies -Wredundant-constraints -Wunused-type-patterns -Wunused-packages
   build-depends:
-      base >=4.16.4.0 && <4.22
+      base >=4.17.2.1 && <4.23
     , bytestring >=0.11.1.0 && <0.13
     , containers >=0.6.3.1 && <0.9
     , data-default >=0.2 && <0.9
-    , stm >=2.5.0.2 && <2.6
-    , text >=1.2.5.0 && <2.2
+    , stm >=2.5.1.0 && <2.6
+    , text >=2.0.2 && <2.2
   default-language: GHC2021
diff --git a/lib/Incipit/Debug.hs b/lib/Incipit/Debug.hs
--- a/lib/Incipit/Debug.hs
+++ b/lib/Incipit/Debug.hs
@@ -6,19 +6,18 @@
 import qualified Data.Text as Text
 import Data.Text (Text)
 import GHC.Stack (CallStack, SrcLoc (..), callStack, getCallStack)
+import System.IO (IO, hPutStrLn, stderr)
 import System.IO.Unsafe (unsafePerformIO)
 
 import Incipit.Base (
   Applicative (pure),
   Functor ((<$)),
   HasCallStack,
-  IO,
   Monad,
   Semigroup ((<>)),
   Show,
   error,
   fromMaybe,
-  putStrLn,
   )
 import Incipit.List (last)
 import Incipit.String.Conversion (ToString (toString), ToText (toText), show)
@@ -33,7 +32,7 @@
   Text ->
   IO ()
 debugPrint SrcLoc {srcLocModule = (toText -> slm), srcLocStartLine} !msg =
-  putStrLn (toString moduleName <> ":" <> show srcLocStartLine <> " " <> toString msg)
+  hPutStrLn stderr (toString moduleName <> ":" <> show srcLocStartLine <> " " <> toString msg)
   where
     moduleName =
       fromMaybe slm (last (Text.splitOn "." slm))
diff --git a/lib/Incipit/Foldable.hs b/lib/Incipit/Foldable.hs
--- a/lib/Incipit/Foldable.hs
+++ b/lib/Incipit/Foldable.hs
@@ -6,7 +6,7 @@
 
 import qualified Data.Foldable as Foldable
 import Data.Foldable (
-  Foldable (elem, fold, foldMap, foldMap', foldl', foldl1, foldr, foldr', foldr1, length, null, product, sum, toList),
+  Foldable (elem, fold, foldMap, foldMap', foldl, foldl', foldl1, foldr, foldr', foldr1, length, null, product, sum, toList),
   all,
   and,
   any,
@@ -25,18 +25,6 @@
   )
 import Data.Maybe (Maybe (Just, Nothing))
 import Data.Ord (Ord, Ordering)
-
--- |Default to using the strict version since the lazy one is so controversial.
-foldl ::
-  ∀ t b a .
-  Foldable t =>
-  (b -> a -> b) ->
-  b ->
-  t a ->
-  b
-foldl =
-  Foldable.foldl'
-{-# inlineable foldl #-}
 
 -- |Safe version of 'Foldable.minimum'.
 minimum ::
diff --git a/lib/Incipit/List.hs b/lib/Incipit/List.hs
--- a/lib/Incipit/List.hs
+++ b/lib/Incipit/List.hs
@@ -29,5 +29,5 @@
 tail :: [a] -> Maybe [a]
 tail = \case
   [] -> Nothing
-  as -> Just (List.tail as)
+  _ : as -> Just as
 {-# inline tail #-}