Fix mystery errors. No idea how I managed to build this earlier.

cabal-install/Distribution/Client/CmdSdist.hs

@@ -211,7 +211,7 @@ packageToSdist verbosity listSources archiveFormat outputFile pkg = do
             
             entries <- execWriterT (evalStateT entriesM [])
             write . GZip.compress . Tar.write $ entries
-            notice verbosity $ "Wrote tarball sdist to " ++ outputPath ++ "\n"
+            notice verbosity $ "Wrote tarball sdist to " ++ outputFile ++ "\n"
         | archiveFormat == ZipFormat ->
             die' verbosity "'.zip' sdists are not yet supported."
 

cabal-install/Distribution/Client/DistDirLayout.hs

@@ -26,7 +26,7 @@ import Data.Maybe (fromMaybe)
 import System.FilePath
 
 import Distribution.Package
-         ( PackageId(..), ComponentId, UnitId )
+         ( PackageId, ComponentId, UnitId )
 import Distribution.Client.Setup
          ( ArchiveFormat(..) )
 import Distribution.Compiler