Fix: Stack image container does not work

fixes #1473

(cherry picked from commit 2301b9b)

Author: borsboom

src/Stack/Nix.hs

@@ -47,7 +47,7 @@ reexecWithOptionalShell inner =
      isReExec <- asks getReExec
      if nixEnable (configNix config) && not inShell && not isReExec
        then runShellAndExit getCmdArgs
-       else liftIO (inner >> exitSuccess)
+       else liftIO inner
   where
     getCmdArgs = do
         args <-

src/main/Main.hs

@@ -809,8 +809,7 @@ withBuildConfigExt go@GlobalOpts{..} mbefore inner mafter = do
                  (lcProjectRoot lc)
                  mbefore
                  (runStackTGlobal manager (lcConfig lc) go $
-                    Nix.reexecWithOptionalShell (inner'' lk0)
-                 )
+                    Nix.reexecWithOptionalShell (inner'' lk0))
                  mafter
                  (Just $ liftIO $
                       do lk' <- readIORef curLk