From 62ca0091f8c37bf0253b2b6897ae472a26b24835 Mon Sep 17 00:00:00 2001
From: Michael Sloan <mgsloan@gmail.com>
Date: Thu, 15 Feb 2018 17:05:12 -0800
Subject: [PATCH] "stack ghci" now replaces the process with ghci for signal
 handling #3821

---
 ChangeLog.md      | 8 +++++++-
 src/Stack/Ghci.hs | 4 ++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/ChangeLog.md b/ChangeLog.md
index 78eecc416a..d745183808 100644
--- a/ChangeLog.md
+++ b/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
diff --git a/src/Stack/Ghci.hs b/src/Stack/Ghci.hs
index 3479a98a5a..e82a3685f2 100644
--- a/src/Stack/Ghci.hs
+++ b/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