Merge pull request #6648 from commercialhaskell/fix6647

Fix #6647 Trigger S-8432 whenever space in Stack's 'programs' directory

ChangeLog.md

@@ -17,6 +17,10 @@ Behavior changes:
   consequently, if a Docker container is not being run 'detached', its standard
   input channel will always be kept open. (Before Docker 1.9.1 the use of an
   interactive container could hang in certain circumstances.)
+* On Windows, Stack will always warn (message S-8432) if there is a space
+  character in Stack's 'programs' path, as GHC 9.4.1 and later do not work if
+  there is a space in the path to the `ghc` executable. S-8432 now presents as a
+  warning and not an error.
 
 Other enhancements:
 

doc/maintainers/stack_errors.md

@@ -542,12 +542,28 @@ to take stock of the errors that Stack itself can raise, by reference to the
 
 *   `Stack.Config.configFromConfigMonoid`:
 
+    Presented as a warning rather than as an error:
+
     ~~~text
-    [S-8432] Stack's 'programs' path contains a space character and has no alternative
+    [S-8432]
+    Stack's 'programs' path is <path>. It contains a space character. This will
+    prevent building with GHC 9.4.1 or later. It also has has no alternative
     short ('8 dot 3') name. This will cause problems with packages that use the
-    GNU project's 'configure' shell script. Use the 'local-programs-path'
-    configuration option to specify an alternative path. The current path is:
-    <path>
+    GNU project's 'configure' shell script.
+
+    To avoid such problems, use the local-programs-path non-project specific
+    configuration option to specify an alternative space-free path.
+    ~~~
+
+    or
+
+    ~~~text
+    [S-8432]
+    Stack's 'programs' path is <path>. It contains a space character. This will
+    prevent building with GHC 9.4.1 or later.
+
+    To avoid such problems, use the local-programs-path non-project specific
+    configuration option to specify an alternative space-free path.
     ~~~
 
 *   `Stack.Coverage.generateHpcReport`: catches exceptions from

src/Stack/Config.hs

@@ -347,20 +347,29 @@ configFromConfigMonoid
       -- exist.
       shortLocalProgramsFilePath <-
         liftIO $ getShortPathName localProgramsFilePath
-      when (' ' `elem` shortLocalProgramsFilePath) $
-        prettyError $
+      prettyWarn $
           "[S-8432]"
           <> line
           <> fillSep
-               [ flow "Stack's 'programs' path contains a space character and \
-                      \has no alternative short ('8 dot 3') name. This will \
-                      \cause problems with packages that use the GNU project's \
-                      \'configure' shell script. Use the"
+               (  [ flow "Stack's 'programs' path is"
+                  , style File (fromString localProgramsFilePath) <> "."
+                  , flow "It contains a space character. This will prevent \
+                         \building with GHC 9.4.1 or later."
+                  ]
+               <> [ flow "It also has no alternative short ('8 dot 3') name. \
+                         \This will cause problems with packages that use the \
+                         \GNU project's 'configure' shell script."
+                  | ' ' `elem` shortLocalProgramsFilePath
+                  ]
+               )
+          <> blankLine
+          <> fillSep
+               [ flow "To avoid sucn problems, use the"
                , style Shell "local-programs-path"
-               , flow "configuration option to specify an alternative path. \
-                      \The current path is:"
-               , style File (fromString localProgramsFilePath) <> "."
+               , flow "non-project specific configuration option to specify an \
+                      \alternative space-free path."
                ]
+          <> line
     platformOnlyDir <-
       runReaderT platformOnlyRelDir (platform, platformVariant)
     let localPrograms = localProgramsBase </> platformOnlyDir