Use readMaybe from Language.Haskell.GhcMod.Read

ghc-mod.cabal

@@ -192,7 +192,6 @@ Executable ghc-mod
                       , GHCMod.Options.Commands
                       , GHCMod.Version
                       , GHCMod.Options.DocUtils
-                      , GHCMod.Options.GapUtils
   GHC-Options:          -Wall -fno-warn-deprecations -threaded
   Default-Extensions:   ConstraintKinds, FlexibleContexts
   HS-Source-Dirs:       src

src/GHCMod/Options/Commands.hs

@@ -4,7 +4,7 @@ import Options.Applicative
 import Options.Applicative.Types
 import Language.Haskell.GhcMod.Types
 import GHCMod.Options.DocUtils
-import GHCMod.Options.GapUtils
+import Language.Haskell.GhcMod.Read
 
 type Symbol = String
 type Expr = String

src/GHCMod/Options/GapUtils.hs

@@ -1,12 +0,0 @@
-{-# LANGUAGE CPP #-}
-
-module GHCMod.Options.GapUtils (
-  readMaybe
-) where
-
-#if __GLASGOW_HASKELL__ >= 706
-import Text.Read (readMaybe)
-#else
-readMaybe :: Read a => String -> Maybe a
-readMaybe = Just . read
-#endif