Add CABAL_DIR environment variable for specifying the cabal directory.

CABAL_DIR can be used to run integration tests independently on Windows,
since setting HOME doesn't affect the location of the APPDATA directory.

Cabal/Distribution/Simple/InstallDirs.hs

@@ -51,6 +51,7 @@ module Distribution.Simple.InstallDirs (
 import Prelude ()
 import Distribution.Compat.Prelude
 
+import Distribution.Compat.Environment (lookupEnv)
 import Distribution.Package
 import Distribution.System
 import Distribution.Compiler
@@ -181,7 +182,11 @@ defaultInstallDirs' True comp userInstall hasLibs = do
 defaultInstallDirs' False comp userInstall _hasLibs = do
   installPrefix <-
       if userInstall
-      then getAppUserDataDirectory "cabal"
+      then do
+        mDir <- lookupEnv "CABAL_DIR"
+        case mDir of
+          Nothing -> getAppUserDataDirectory "cabal"
+          Just dir -> return dir
       else case buildOS of
            Windows -> do windowsProgramFilesDir <- getWindowsProgramFilesDir
                          return (windowsProgramFilesDir </> "Haskell")

cabal-install/Distribution/Client/CmdInstall.hs

@@ -32,7 +32,7 @@ import Distribution.Client.ProjectConfig.Types
          , projectConfigBuildOnly, projectConfigDistDir
          , projectConfigConfigFile )
 import Distribution.Client.Config
-         ( defaultCabalDir )
+         ( getCabalDir )
 import Distribution.Client.ProjectConfig
          ( readGlobalConfig, resolveBuildTimeSettings )
 import Distribution.Client.DistDirLayout
@@ -250,7 +250,7 @@ establishDummyProjectBaseContext
   -> IO ProjectBaseContext
 establishDummyProjectBaseContext verbosity cliConfig tmpDir localPackages = do
 
-    cabalDir <- defaultCabalDir
+    cabalDir <- getCabalDir
 
     -- Create the dist directories
     createDirectoryIfMissingVerbose verbosity True $ distDirectory distDirLayout

cabal-install/Distribution/Client/Config.hs

@@ -22,7 +22,7 @@ module Distribution.Client.Config (
     showConfigWithComments,
     parseConfig,
 
-    defaultCabalDir,
+    getCabalDir,
     defaultConfigFile,
     defaultCacheDir,
     defaultCompiler,
@@ -124,7 +124,7 @@ import System.FilePath
 import System.IO.Error
          ( isDoesNotExistError )
 import Distribution.Compat.Environment
-         ( getEnvironment )
+         ( getEnvironment, lookupEnv )
 import Distribution.Compat.Exception
          ( catchIO )
 import qualified Paths_cabal_install
@@ -431,7 +431,7 @@ instance Semigroup SavedConfig where
 --
 baseSavedConfig :: IO SavedConfig
 baseSavedConfig = do
-  userPrefix <- defaultCabalDir
+  userPrefix <- getCabalDir
   cacheDir   <- defaultCacheDir
   logsDir    <- defaultLogsDir
   worldFile  <- defaultWorldFile
@@ -481,40 +481,45 @@ initialSavedConfig = do
     }
   }
 
---TODO: misleading, there's no way to override this default
---      either make it possible or rename to simply getCabalDir.
 defaultCabalDir :: IO FilePath
 defaultCabalDir = getAppUserDataDirectory "cabal"
 
+getCabalDir :: IO FilePath
+getCabalDir = do
+  mDir <- lookupEnv "CABAL_DIR"
+  case mDir of
+    Nothing -> defaultCabalDir
+    Just dir -> return dir
+
 defaultConfigFile :: IO FilePath
 defaultConfigFile = do
-  dir <- defaultCabalDir
+  dir <- getCabalDir
   return $ dir </> "config"
 
 defaultCacheDir :: IO FilePath
 defaultCacheDir = do
-  dir <- defaultCabalDir
+  dir <- getCabalDir
   return $ dir </> "packages"
 
 defaultLogsDir :: IO FilePath
 defaultLogsDir = do
-  dir <- defaultCabalDir
+  dir <- getCabalDir
   return $ dir </> "logs"
 
 -- | Default position of the world file
 defaultWorldFile :: IO FilePath
 defaultWorldFile = do
-  dir <- defaultCabalDir
+  dir <- getCabalDir
   return $ dir </> "world"
 
 defaultExtraPath :: IO [FilePath]
 defaultExtraPath = do
-  dir <- defaultCabalDir
+  dir <- getCabalDir
   return [dir </> "bin"]
 
 defaultSymlinkPath :: IO FilePath
 defaultSymlinkPath = do
-  dir <- defaultCabalDir
+  dir <- getCabalDir
   return (dir </> "bin")
 
 defaultCompiler :: CompilerFlavor

cabal-install/Distribution/Client/Install.hs

@@ -80,7 +80,7 @@ import Distribution.Client.Setup
          , ConfigFlags(..), configureCommand, filterConfigureFlags
          , ConfigExFlags(..), InstallFlags(..) )
 import Distribution.Client.Config
-         ( defaultCabalDir, defaultUserInstall )
+         ( getCabalDir, defaultUserInstall )
 import Distribution.Client.Sandbox.Timestamp
          ( withUpdateTimestamps )
 import Distribution.Client.Sandbox.Types
@@ -858,7 +858,7 @@ postInstallActions verbosity
 storeDetailedBuildReports :: Verbosity -> FilePath
                           -> [(BuildReports.BuildReport, Maybe Repo)] -> IO ()
 storeDetailedBuildReports verbosity logsDir reports = sequence_
-  [ do dotCabal <- defaultCabalDir
+  [ do dotCabal <- getCabalDir
        let logFileName = display (BuildReports.package report) <.> "log"
            logFile     = logsDir </> logFileName
            reportsDir  = dotCabal </> "reports" </> remoteRepoName remoteRepo

cabal-install/Distribution/Client/ProjectOrchestration.hs

@@ -115,7 +115,7 @@ import           Distribution.Client.TargetSelector
                    , ComponentKind(..), componentKind
                    , readTargetSelectors, reportTargetSelectorProblems )
 import           Distribution.Client.DistDirLayout
-import           Distribution.Client.Config (defaultCabalDir)
+import           Distribution.Client.Config (getCabalDir)
 import           Distribution.Client.Setup hiding (packageName)
 import           Distribution.Types.ComponentName
                    ( componentNameString )
@@ -171,7 +171,7 @@ establishProjectBaseContext :: Verbosity
                             -> IO ProjectBaseContext
 establishProjectBaseContext verbosity cliConfig = do
 
-    cabalDir <- defaultCabalDir
+    cabalDir <- getCabalDir
     projectRoot <- either throwIO return =<<
                    findProjectRoot Nothing mprojectFile
 

cabal-install/Distribution/Client/SetupWrapper.hs

@@ -75,7 +75,7 @@ import Distribution.Simple.PackageIndex (InstalledPackageIndex)
 import qualified Distribution.InstalledPackageInfo as IPI
 import Distribution.Client.Types
 import Distribution.Client.Config
-         ( defaultCabalDir )
+         ( getCabalDir )
 import Distribution.Client.IndexUtils
          ( getInstalledPackages )
 import Distribution.Client.JobControl
@@ -780,7 +780,7 @@ getExternalSetupMethod verbosity options pkg bt = do
   cachedSetupDirAndProg :: SetupScriptOptions -> Version
                         -> IO (FilePath, FilePath)
   cachedSetupDirAndProg options' cabalLibVersion = do
-    cabalDir <- defaultCabalDir
+    cabalDir <- getCabalDir
     let setupCacheDir       = cabalDir </> "setup-exe-cache"
         cachedSetupProgFile = setupCacheDir
                               </> ("setup-" ++ buildTypeString ++ "-"

cabal-install/Distribution/Client/Upload.hs

@@ -172,7 +172,7 @@ report verbosity repoCtxt mUsername mPassword = do
       repos       = repoContextRepos repoCtxt
       remoteRepos = mapMaybe maybeRepoRemote repos
   forM_ remoteRepos $ \remoteRepo ->
-      do dotCabal <- defaultCabalDir
+      do dotCabal <- getCabalDir
          let srcDir = dotCabal </> "reports" </> remoteRepoName remoteRepo
          -- We don't want to bomb out just because we haven't built any packages
          -- from this repo yet.

cabal-install/tests/IntegrationTests2.hs

@@ -9,7 +9,7 @@ module IntegrationTests2 where
 
 import Distribution.Client.DistDirLayout
 import Distribution.Client.ProjectConfig
-import Distribution.Client.Config (defaultCabalDir)
+import Distribution.Client.Config (getCabalDir)
 import Distribution.Client.TargetSelector hiding (DirActions(..))
 import qualified Distribution.Client.TargetSelector as TS (DirActions(..))
 import Distribution.Client.ProjectPlanning
@@ -1463,7 +1463,7 @@ type ProjDetails = (DistDirLayout,
 
 configureProject :: FilePath -> ProjectConfig -> IO ProjDetails
 configureProject testdir cliConfig = do
-    cabalDir <- defaultCabalDir
+    cabalDir <- getCabalDir
     let cabalDirLayout = defaultCabalDirLayout cabalDir
 
     projectRootDir <- canonicalizePath (basedir </> testdir)