Fix #6583 Error S-6362 acknowledges compiler set at command line

ChangeLog.md

@@ -74,6 +74,8 @@ Bug fixes:
   that form.
 * On Unix-like operating systems, the `test --coverage` command now finds
   package keys even for very long package names.
+* The Error S-6362 message now acknowledges when the wanted compiler has been
+  specified at the command line.
 
 ## v2.15.7 - 2024-05-12
 

doc/maintainers/stack_errors.md

@@ -5,7 +5,7 @@
 In connection with considering Stack's support of the
 [Haskell Error Index](https://errors.haskell.org/) initiative, this page seeks
 to take stock of the errors that Stack itself can raise, by reference to the
-`master` branch of the Stack repository. Last updated: 2024-05-05.
+`master` branch of the Stack repository. Last updated: 2024-05-17.
 
 *   `Stack.main`: catches exceptions from action `commandLineHandler`.
 
@@ -384,7 +384,7 @@ to take stock of the errors that Stack itself can raise, by reference to the
         [S-8664] | InvalidFlagSpecification [UnusedFlags]
         [S-8100] | GHCProfOptionInvalid
         [S-1727] | NotOnlyLocal [PackageName] [Text]
-        [S-6362] | CompilerVersionMismatch (Maybe (ActualCompiler, Arch)) (WantedCompiler, Arch) GHCVariant CompilerBuild VersionCheck (Maybe (Path Abs File)) Text
+        [S-6362] | CompilerVersionMismatch (Maybe (ActualCompiler, Arch)) (WantedCompiler, Arch) GHCVariant CompilerBuild VersionCheck WantedCompilerSetter Text
         ~~~
 
     -   `Stack.Types.Compiler.CompilerException`

package.yaml

@@ -341,6 +341,7 @@ library:
   - Stack.Types.UploadOpts
   - Stack.Types.Version
   - Stack.Types.VersionedDownloadInfo
+  - Stack.Types.WantedCompilerSetter
   - Stack.Uninstall
   - Stack.Unpack
   - Stack.Update

src/Stack/Setup.hs

@@ -158,17 +158,19 @@ import           Stack.Types.GHCVariant
                    ( GHCVariant (..), HasGHCVariant (..), ghcVariantName
                    , ghcVariantSuffix
                    )
+import           Stack.Types.GlobalOpts ( GlobalOpts (..) )
 import           Stack.Types.Platform
                    ( HasPlatform (..), PlatformVariant (..)
                    , platformOnlyRelDir )
-import           Stack.Types.Runner ( HasRunner (..) )
+import           Stack.Types.Runner ( HasRunner (..), Runner (..) )
 import           Stack.Types.SetupInfo ( SetupInfo (..) )
 import           Stack.Types.SourceMap
                    ( SMActual (..), SMWanted (..), SourceMap (..) )
 import           Stack.Types.Version
                    ( VersionCheck, stackMinorVersion, stackVersion )
 import           Stack.Types.VersionedDownloadInfo
                    ( VersionedDownloadInfo (..) )
+import           Stack.Types.WantedCompilerSetter ( WantedCompilerSetter (..) )
 import qualified System.Directory as D
 import           System.Environment ( getExecutablePath, lookupEnv )
 import           System.IO.Error ( isPermissionError )
@@ -1156,6 +1158,11 @@ installGhcBindist sopts getSetupInfo' installed = do
             (Just tool, False) -> [(tool, compilerBuild)]
             _ -> [])
         possibleCompilers
+      globalOpts = config.runner.globalOpts
+      wantedCompilerSetter
+        | isJust globalOpts.compiler = CompilerAtCommandLine
+        | isJust globalOpts.snapshot = SnapshotAtCommandLine
+        | otherwise = YamlConfiguration sopts.stackYaml
   logDebug $
        "Found already installed GHC builds: "
     <> mconcat (intersperse ", " (map (fromString . compilerBuildName . snd) existingCompilers))
@@ -1200,7 +1207,7 @@ installGhcBindist sopts getSetupInfo' installed = do
               [] -> CompilerBuildStandard
               (_, compilerBuild):_ -> compilerBuild)
             sopts.compilerCheck
-            sopts.stackYaml
+            wantedCompilerSetter
             suggestion
 
 -- | Ensure compiler is installed.

src/Stack/Types/Build/Exception.hs

@@ -41,6 +41,7 @@ import           Stack.Types.NamedComponent
 import           Stack.Types.Package ( Package (..), packageIdentifier )
 import           Stack.Types.ParentMap ( ParentMap )
 import           Stack.Types.Version ( VersionCheck (..), VersionRange )
+import           Stack.Types.WantedCompilerSetter ( WantedCompilerSetter (..) )
 
 -- | Type representing exceptions thrown by functions exported by modules with
 -- names beginning @Stack.Build@.
@@ -257,7 +258,7 @@ data BuildPrettyException
       GHCVariant -- expected
       CompilerBuild -- expected
       VersionCheck
-      (Maybe (Path Abs File)) -- Path to the stack.yaml file
+      WantedCompilerSetter -- Way that the wanted compiler is set
       StyleDoc -- recommended resolution
   deriving (Show, Typeable)
 
@@ -390,7 +391,15 @@ instance Pretty BuildPrettyException where
                     (map (fromString . T.unpack) exes :: [StyleDoc])
                 )
            <> line
-  pretty (CompilerVersionMismatch mactual (expected, eArch) ghcVariant ghcBuild check mstack resolution) =
+  pretty ( CompilerVersionMismatch
+             mactual
+             (expected, eArch)
+             ghcVariant
+             ghcBuild
+             check
+             wantedCompilerSetter
+             resolution
+         ) =
     "[S-6362]"
     <> line
     <> fillSep
@@ -415,12 +424,25 @@ instance Pretty BuildPrettyException where
          ,    parens
                 ( fillSep
                     [ flow "based on"
-                    , case mstack of
-                        Nothing -> flow "command line arguments"
-                        Just stack -> fillSep
-                          [ flow "snapshot setting in"
-                          , pretty stack
+                    , case wantedCompilerSetter of
+                        CompilerAtCommandLine -> fillSep
+                          [ "the"
+                          , style Shell "--compiler"
+                          , "option"
                           ]
+                        SnapshotAtCommandLine -> fillSep
+                          [ "the"
+                          , style Shell "--snapshot" <> ","
+                          , "or"
+                          , style Shell "--resolver" <> ","
+                          , "option"
+                          ]
+                        YamlConfiguration mStack -> case mStack of
+                          Nothing -> flow "command line arguments"
+                          Just stack -> fillSep
+                            [ flow "the configuration in"
+                            , pretty stack
+                            ]
                     ]
                 )
           <> "."

src/Stack/Types/WantedCompilerSetter.hs

@@ -0,0 +1,17 @@
+{-# LANGUAGE NoImplicitPrelude #-}
+
+module Stack.Types.WantedCompilerSetter
+  ( WantedCompilerSetter (..)
+  ) where
+
+import           Stack.Prelude
+
+-- | Type representing ways that a wanted compiler is set.
+data WantedCompilerSetter
+  = CompilerAtCommandLine
+    -- ^ At the command line with --compiler option.
+  | SnapshotAtCommandLine
+    -- ^ At the command line with --snapshot (or --resolver) option.
+  | YamlConfiguration (Maybe (Path Abs File))
+    -- ^ Via a YAML configuration file.
+  deriving (Show, Typeable)

stack.cabal

@@ -336,6 +336,7 @@ library
       Stack.Types.UploadOpts
       Stack.Types.Version
       Stack.Types.VersionedDownloadInfo
+      Stack.Types.WantedCompilerSetter
       Stack.Uninstall
       Stack.Unpack
       Stack.Update