Have "stack script" set import search path #3377

ChangeLog.md

@@ -46,6 +46,12 @@ Major changes:
 Behavior changes:
 * `stack.yaml` now supports `snapshot`: a synonym for `resolver`. See [#4256](https://github.com/commercialhaskell/stack/issues/4256)
 
+* `stack script` now passes `-i -idir` in to the `ghc`
+  invocation. This makes it so that the script can import local
+  modules, and fixes an issue where `.hs` files in the current
+  directory could affect interpretation of the script. See
+  [#4538](https://github.com/commercialhaskell/stack/pull/4538)
+
 Other enhancements:
 
 * Defer loading up of files for local packages. This allows us to get

src/Stack/Script.hs

@@ -35,11 +35,12 @@ import qualified RIO.Text as T
 scriptCmd :: ScriptOpts -> GlobalOpts -> IO ()
 scriptCmd opts go' = do
     file <- resolveFile' $ soFile opts
-    let go = go'
+    let scriptDir = parent file
+        go = go'
             { globalConfigMonoid = (globalConfigMonoid go')
                 { configMonoidInstallGHC = First $ Just True
                 }
-            , globalStackYaml = SYLNoConfig $ parent file
+            , globalStackYaml = SYLNoConfig scriptDir
             }
     withDefaultBuildConfigAndLock go $ \lk -> do
       -- Some warnings in case the user somehow tries to set a
@@ -92,7 +93,8 @@ scriptCmd opts go' = do
                     withNewLocalBuildTargets targets $ Stack.Build.build Nothing lk
 
         let ghcArgs = concat
-                [ ["-hide-all-packages"]
+                [ ["-i", "-i" ++ toFilePath scriptDir]
+                , ["-hide-all-packages"]
                 , maybeToList colorFlag
                 , map (\x -> "-package" ++ x)
                     $ Set.toList
@@ -109,13 +111,12 @@ scriptCmd opts go' = do
           SEInterpret -> exec ("run" ++ compilerExeName wc)
                 (ghcArgs ++ toFilePath file : soArgs opts)
           _ -> do
-            let dir = parent file
             -- Use readProcessStdout_ so that (1) if GHC does send any output
             -- to stdout, we capture it and stop it from being sent to our
             -- stdout, which could break scripts, and (2) if there's an
             -- exception, the standard output we did capture will be reported
             -- to the user.
-            withWorkingDir (toFilePath dir) $ proc
+            withWorkingDir (toFilePath scriptDir) $ proc
               (compilerExeName wc)
               (ghcArgs ++ [toFilePath file])
               (void . readProcessStdout_)