"stack ghci" now replaces the process with ghci for signal handling #3821

Author: mgsloan

ChangeLog.md

@@ -52,6 +52,13 @@ Other enhancements:
 
 Bug fixes:
 
+* `stack ghci` now replaces the stack process with ghci. This improves
+  signal handling behavior. In particular, handling of Ctrl-C.  To make
+  this possible, the generated files are now left behind after exit.
+  The paths are based on hashing file contents, and it's stored in the
+  system temporary directory, so this shouldn't result in too much
+  garbage. See
+  [#3821](https://github.com/commercialhaskell/stack/issues/3821).
 
 
 ## v1.6.5
@@ -108,7 +115,6 @@ Bug fixes:
 * `stack ghci` now uses correct paths for autogen files with
   [#3791](https://github.com/commercialhaskell/stack/issues/3791)
 
-
 ## v1.6.3.1
 
 Hackage-only release with no user facing changes (updated to build with

src/Stack/Ghci.hs

@@ -32,6 +32,7 @@ import           Path
 import           Path.Extra (toFilePathNoTrailingSep)
 import           Path.IO hiding (withSystemTempDir)
 import qualified RIO
+import           RIO.Process (HasProcessContext, exec, proc, readProcess_)
 import           Stack.Build
 import           Stack.Build.Installed
 import           Stack.Build.Source
@@ -51,7 +52,6 @@ import           Stack.Types.PackageIdentifier
 import           Stack.Types.PackageName
 import           Stack.Types.Runner
 import           System.IO (putStrLn, putStr, getLine)
-import           RIO.Process (HasProcessContext, execSpawn, proc, readProcess_)
 import           System.IO.Temp (getCanonicalTemporaryDirectory)
 
 #ifndef WINDOWS
@@ -368,7 +368,7 @@ runGhci GhciOpts{..} targets mainIsTargets pkgs extraFiles exposePackages = do
       mconcat (intersperse ", " (map (RIO.display . ghciPkgName) pkgs))
     let execGhci extras = do
             menv <- liftIO $ configProcessContextSettings config defaultEnvSettings
-            withProcessContext menv $ execSpawn
+            withProcessContext menv $ exec
                  (fromMaybe (compilerExeName wc) ghciGhcCommand)
                  (("--interactive" : ) $
                  -- This initial "-i" resets the include directories to