Add GHC Unit ID store to cabal path output

The GHC "Project Unit ID" store path has been used in cabal-install
since 3.12.1.0.

Resolves: #10165

Author: sgillespie

cabal-install/src/Distribution/Client/CmdPath.hs

@@ -25,7 +25,7 @@ import Distribution.Client.Config
   , defaultStoreDir
   , getConfigFilePath
   )
-import Distribution.Client.DistDirLayout (CabalDirLayout (..), distProjectRootDirectory)
+import Distribution.Client.DistDirLayout (CabalDirLayout (..), distProjectRootDirectory, StoreDirLayout (..))
 import Distribution.Client.Errors
 import Distribution.Client.GlobalFlags
 import Distribution.Client.NixStyleOptions
@@ -208,6 +208,7 @@ data ConfigPath
   | ConfigPathStoreDir
   | ConfigPathConfigFile
   | ConfigPathInstallDir
+  | ConfigPathProjectUnitId
   deriving (Eq, Ord, Show, Enum, Bounded)
 
 -- | The configuration name for this path.
@@ -218,6 +219,7 @@ pathName ConfigPathLogsDir = "logs-dir"
 pathName ConfigPathStoreDir = "store-dir"
 pathName ConfigPathConfigFile = "config-file"
 pathName ConfigPathInstallDir = "installdir"
+pathName ConfigPathProjectUnitId = "project-unit-id"
 
 -------------------------------------------------------------------------------
 -- Action
@@ -240,17 +242,20 @@ pathAction flags@NixStyleFlags{extraFlags = pathFlags'} cliTargetStrings globalF
   when (buildSettingDryRun (buildSettings baseCtx)) $
     dieWithException verbosity CmdPathCommandDoesn'tSupportDryRun
 
+  (compiler, _, progDb) <- 
+    runRebuild (distProjectRootDirectory . distDirLayout $ baseCtx) $
+      configureCompiler verbosity (distDirLayout baseCtx) (projectConfig baseCtx)
+
   compilerPathOutputs <-
     if not $ fromFlagOrDefault False (pathCompiler pathFlags)
       then pure Nothing
       else do
-        (compiler, _, progDb) <- runRebuild (distProjectRootDirectory . distDirLayout $ baseCtx) $ configureCompiler verbosity (distDirLayout baseCtx) (projectConfig baseCtx)
         compilerProg <- requireCompilerProg verbosity compiler
         (configuredCompilerProg, _) <- requireProgram verbosity compilerProg progDb
         pure $ Just $ mkCompilerInfo configuredCompilerProg compiler
 
   paths <- for (fromFlagOrDefault [] $ pathDirectories pathFlags) $ \p -> do
-    t <- getPathLocation verbosity baseCtx p
+    t <- getPathLocation verbosity baseCtx compiler p
     pure (pathName p, t)
 
   let pathOutputs =
@@ -272,23 +277,25 @@ pathAction flags@NixStyleFlags{extraFlags = pathFlags'} cliTargetStrings globalF
 -- | Find the FilePath location for common configuration paths.
 --
 -- TODO: this should come from a common source of truth to avoid code path divergence
-getPathLocation :: Verbosity -> ProjectBaseContext -> ConfigPath -> IO FilePath
-getPathLocation _ _ ConfigPathCacheHome =
+getPathLocation :: Verbosity -> ProjectBaseContext -> Compiler -> ConfigPath -> IO FilePath
+getPathLocation _ _ _ ConfigPathCacheHome =
   defaultCacheHome
-getPathLocation _ baseCtx ConfigPathRemoteRepoCache =
+getPathLocation _ baseCtx _ ConfigPathRemoteRepoCache =
   pure $ buildSettingCacheDir (buildSettings baseCtx)
-getPathLocation _ baseCtx ConfigPathLogsDir =
+getPathLocation _ baseCtx _ ConfigPathLogsDir =
   pure $ cabalLogsDirectory (cabalDirLayout baseCtx)
-getPathLocation _ baseCtx ConfigPathStoreDir =
+getPathLocation _ baseCtx _ ConfigPathStoreDir =
   fromFlagOrDefault
     defaultStoreDir
     (pure <$> projectConfigStoreDir (projectConfigShared (projectConfig baseCtx)))
-getPathLocation verbosity baseCtx ConfigPathConfigFile =
+getPathLocation verbosity baseCtx _ ConfigPathConfigFile =
   getConfigFilePath verbosity (projectConfigConfigFile (projectConfigShared (projectConfig baseCtx)))
-getPathLocation _ baseCtx ConfigPathInstallDir =
+getPathLocation _ baseCtx _ ConfigPathInstallDir =
   fromFlagOrDefault
     defaultInstallPath
     (pure <$> cinstInstalldir (projectConfigClientInstallFlags $ projectConfigBuildOnly (projectConfig baseCtx)))
+getPathLocation _ baseCtx compiler ConfigPathProjectUnitId =
+  pure $ storeDirectory (cabalStoreDirLayout (cabalDirLayout baseCtx)) compiler
 
 -- ----------------------------------------------------------------------------
 -- Helpers for determining compiler information