Fix #6675 Add install-msys and ancillary matters

ChangeLog.md

@@ -17,6 +17,14 @@ Behavior changes:
 
 Other enhancements:
 
+* In YAML configuration files, the `install-msys` key is introduced, to enable
+  or disable the download and installation of Stack-supplied MSYS2 when
+  necessary (subject to `skip-msys: false`). The default is the same as the
+  `install-ghc` setting (including if that is set at the command line).
+  Consequently, the default behaviour of Stack is unaffected.
+* Add the `stack config set install-msys` command to configure the
+  `install-msys` option in YAML configuration files.
+
 Bug fixes:
 
 ## v3.3.1 - 2024-12-28

doc/commands/config_command.md

@@ -48,6 +48,8 @@ stack config set COMMAND
 Available commands:
   install-ghc              Configure whether or not Stack should automatically
                            install GHC when necessary.
+  install-msys             Configure whether or not Stack should automatically
+                           install MSYS2 when necessary.
   package-index            Configure Stack's package index
   recommend-stack-upgrade  Configure whether or not Stack should notify the user
                            if it identifes a new version of Stack is available.
@@ -79,6 +81,21 @@ the project-level configuration file (`stack.yaml`, by default) is altered. The
 `--global` flag specifies the user-specific global configuration file
 (`config.yaml`).
 
+## The `stack config set install-msys` command
+
+:octicons-tag-24: UNRELEASED
+
+~~~text
+stack config set install-msys [--global] true|false
+~~~
+
+`stack config set install-msys true` or `false` sets the
+[`install-msys`](../configure/yaml/non-project.md#install-msys) non-project
+specific configuration option in a configuration file, accordingly. By default,
+the project-level configuration file (`stack.yaml`, by default) is altered. The
+`--global` flag specifies the user-specific global configuration file
+(`config.yaml`).
+
 ## The `stack config set package-index download-prefix` command
 
 [:octicons-tag-24: 2.9.3](https://github.com/commercialhaskell/stack/releases/tag/v2.9.3)

doc/commands/setup_command.md

@@ -7,7 +7,7 @@ stack setup [GHC_VERSION] [--[no-]reinstall] [--ghc-bindist URL]
             [--ghcjs-boot-options GHCJS_BOOT] [--[no-]ghcjs-boot-clean]
 ~~~
 
-`stack setup` attempts to install a version of GHC.
+`stack setup` attempts to install a version of GHC and, on Windows, MSYS2.
 
 By default:
 
@@ -28,8 +28,9 @@ option specifying a custom GHC variant. For further information about the
 specific configuration option documentation.
 
 If Stack is configured not to install GHC (`install-ghc: false` or passing the
-`--no-install-ghc` flag) then `stack setup` will warn that the flag and the
-command are inconsistent and take no action.
+`--no-install-ghc` flag) or not to install MSYS2 (`install-msys: false` or
+passing the `--no-install-msys` flag) then `stack setup` will warn that the flag
+and the command are inconsistent and take no action.
 
 === "Linux"
 

doc/configure/global_flags.md

@@ -150,6 +150,23 @@ Stack-supplied MSYS2 when necessary. For further information, see the
 documentation for the corresponding non-project specific configuration
 [option](yaml/non-project.md#install-ghc).
 
+## `--[no-]install-msys` flag
+
+:octicons-tag-24: UNRELEASED
+
+Restrictions: Windows systems only
+
+Default: Same as the [`install-ghc`](yaml/non-project.md#install-ghc) setting
+(including if that is set on the command line)
+
+If Stack is checking for the Stack-supplied MSYS2 when Stack is setting up the
+environment, enables/disables the download and installation of MSYS2 when
+necessary. For further information, see the documentation for the corresponding
+non-project specific configuration [option](yaml/non-project.md#install-msys).
+
+To skip entirely checking for the Stack-supplied MSYS2, see the documentation
+for the [`skip-msys`](yaml/non-project.md#skip-msys) configuration option.
+
 ## `--jobs` or `-j` option
 
 Pass the option `--jobs <number_of_jobs>` to specify the number of concurrent
@@ -269,6 +286,9 @@ environment. For further information, see the documentation for the
 corresponding non-project specific configuration
 [option](yaml/non-project.md#skip-msys).
 
+To prevent installation of MSYS2, if it is not installed, see the documentation
+for the [`install-msys`](yaml/non-project.md#install-msys) configuration option.
+
 ## `--snapshot` option
 
 [:octicons-tag-24: 2.15.1](https://github.com/commercialhaskell/stack/releases/tag/v2.15.1)

doc/configure/yaml/non-project.md

@@ -872,12 +872,31 @@ will receive a warning if this configuration value is set.
 Default: `true`
 ([:octicons-tag-24: 1.5.0](https://github.com/commercialhaskell/stack/releases/tag/v1.5.0))
 
-Command line equivalent (takes precedence): `--[no-]install-ghc` flag
+Command line equivalent (takes precedence):
+[`--[no-]install-ghc`](../global_flags.md#-no-install-ghc-flag) flag
 
 Whether or not to download and install GHC when necessary. On Windows,
 `install-ghc: false` also disables the download and installation of the
 Stack-supplied MSYS2 when necessary.
 
+## install-msys
+
+:octicons-tag-24: UNRELEASED
+
+Restrictions: Windows systems only
+
+Default: same as the [`install-ghc`](#install-ghc) setting (including if that is
+set on the command line)
+
+Command line equivalent (takes precedence):
+[`--[no-]install-msys`](../global_flags.md#-no-install-msys-flag) flag
+
+If Stack is checking for the Stack-supplied MSYS2 when Stack is setting up the
+environment, whether or not to download and install MSYS2 when necessary.
+
+To skip entirely checking for the Stack-supplied MSYS2, see the documentation
+for the [`skip-msys`](#skip-msys) configuration option.
+
 ## jobs
 
 Default: the number of CPUs (cores) that the machine has.
@@ -1481,6 +1500,9 @@ Command line equivalent (takes precedence):
 Skips checking for the Stack-supplied MSYS2 (and installing that MSYS2, if it is
 not installed) when Stack is setting up the environment.
 
+To prevent installation of MSYS2, if it is not installed, see the documentation
+for the [`install-msys`](#install-msys) configuration option.
+
 ~~~yaml
 skip-msys: true
 ~~~

src/Stack/Config.hs

@@ -286,6 +286,7 @@ configFromConfigMonoid
           configMonoid.compilerRepository
         ghcBuild = getFirst configMonoid.ghcBuild
         installGHC = fromFirstTrue configMonoid.installGHC
+        installMsys = fromFirst installGHC configMonoid.installMsys
         skipGHCCheck = fromFirstFalse configMonoid.skipGHCCheck
         skipMsys = fromFirstFalse configMonoid.skipMsys
         defMsysEnvironment = case platform of
@@ -587,6 +588,7 @@ configFromConfigMonoid
                 , latestSnapshot
                 , systemGHC
                 , installGHC
+                , installMsys
                 , skipGHCCheck
                 , skipMsys
                 , msysEnvironment

src/Stack/ConfigCmd.hs

@@ -43,6 +43,7 @@ import           Stack.Prelude
 import           Stack.Types.Config ( Config (..), HasConfig (..) )
 import           Stack.Types.ConfigMonoid
                    ( configMonoidInstallGHCName
+                   , configMonoidInstallMsysName
                    , configMonoidRecommendStackUpgradeName
                    , configMonoidSystemGHCName
                    )
@@ -71,6 +72,7 @@ data ConfigCmdSet
   | ConfigCmdSetResolver !(Unresolved AbstractSnapshot)
   | ConfigCmdSetSystemGhc !CommandScope !Bool
   | ConfigCmdSetInstallGhc !CommandScope !Bool
+  | ConfigCmdSetInstallMsys !CommandScope !Bool
   | ConfigCmdSetRecommendStackUpgrade !CommandScope !Bool
   | ConfigCmdSetDownloadPrefix !CommandScope !Text
 
@@ -86,6 +88,7 @@ configCmdSetScope (ConfigCmdSetSnapshot _) = CommandScopeProject
 configCmdSetScope (ConfigCmdSetResolver _) = CommandScopeProject
 configCmdSetScope (ConfigCmdSetSystemGhc scope _) = scope
 configCmdSetScope (ConfigCmdSetInstallGhc scope _) = scope
+configCmdSetScope (ConfigCmdSetInstallMsys scope _) = scope
 configCmdSetScope (ConfigCmdSetRecommendStackUpgrade scope _) = scope
 configCmdSetScope (ConfigCmdSetDownloadPrefix scope _) = scope
 
@@ -267,6 +270,7 @@ cfgCmdSetValue root (ConfigCmdSetResolver newSnapshot) =
   snapshotValue root newSnapshot
 cfgCmdSetValue _ (ConfigCmdSetSystemGhc _ bool') = pure $ Yaml.Bool bool'
 cfgCmdSetValue _ (ConfigCmdSetInstallGhc _ bool') = pure $ Yaml.Bool bool'
+cfgCmdSetValue _ (ConfigCmdSetInstallMsys _ bool') = pure $ Yaml.Bool bool'
 cfgCmdSetValue _ (ConfigCmdSetRecommendStackUpgrade _ bool') =
   pure $ Yaml.Bool bool'
 cfgCmdSetValue _ (ConfigCmdSetDownloadPrefix _ url) = pure $ Yaml.String url
@@ -288,6 +292,7 @@ cfgCmdSetKeys (ConfigCmdSetSnapshot _) = [["snapshot"], ["resolver"]]
 cfgCmdSetKeys (ConfigCmdSetResolver _) = [["resolver"], ["snapshot"]]
 cfgCmdSetKeys (ConfigCmdSetSystemGhc _ _) = [[configMonoidSystemGHCName]]
 cfgCmdSetKeys (ConfigCmdSetInstallGhc _ _) = [[configMonoidInstallGHCName]]
+cfgCmdSetKeys (ConfigCmdSetInstallMsys _ _) = [[configMonoidInstallMsysName]]
 cfgCmdSetKeys (ConfigCmdSetRecommendStackUpgrade _ _) =
   [[configMonoidRecommendStackUpgradeName]]
 cfgCmdSetKeys (ConfigCmdSetDownloadPrefix _ _) =
@@ -341,6 +346,14 @@ configCmdSetParser =
               ( OA.progDesc
                   "Configure whether or not Stack should automatically install \
                   \GHC when necessary." ))
+      , OA.command (T.unpack configMonoidInstallMsysName)
+          ( OA.info
+              (   ConfigCmdSetInstallMsys
+              <$> globalScopeFlag
+              <*> boolArgument )
+              ( OA.progDesc
+                  "Configure whether or not Stack should automatically install \
+                  \MSYS2 when necessary." ))
       , OA.command (T.unpack configMonoidRecommendStackUpgradeName)
           ( OA.info
               (   ConfigCmdSetRecommendStackUpgrade

src/Stack/Options/ConfigParser.hs

@@ -33,7 +33,7 @@ import qualified System.FilePath as FilePath
 -- | Command-line arguments parser for configuration.
 configOptsParser :: FilePath -> GlobalOptsContext -> Parser ConfigMonoid
 configOptsParser currentDir hide0 =
-  ( \stackRoot workDir buildOpts dockerOpts nixOpts systemGHC installGHC arch
+  ( \stackRoot workDir buildOpts dockerOpts nixOpts systemGHC installGHC installMsys arch
      ghcVariant ghcBuild jobs extraIncludeDirs extraLibDirs
      customPreprocessorExts overrideGccPath overrideHpack hpackForce skipGHCCheck skipMsys
      localBinPath setupInfoLocations modifyCodePage allowDifferentUser dumpLogs
@@ -45,6 +45,7 @@ configOptsParser currentDir hide0 =
        , nixOpts
        , systemGHC
        , installGHC
+       , installMsys
        , skipGHCCheck
        , arch
        , ghcVariant
@@ -100,6 +101,11 @@ configOptsParser currentDir hide0 =
         "downloading and installing GHC if necessary. (Can be done manually \
         \with 'stack setup'.)"
         hide
+  <*> firstBoolFlagsNoDefault
+        "install-msys"
+        "downloading and installing MSYS2 if necessary (Windows only). (Can be \
+        \done manually with 'stack setup'.) (default: same as 'install-ghc')"
+        hide
   <*> optionalFirst (strOption
         (  long "arch"
         <> metavar "ARCH"

src/Stack/Setup.hs

@@ -620,7 +620,8 @@ defaultSetupInfoYaml =
   "https://raw.githubusercontent.com/commercialhaskell/stackage-content/master/stack/stack-setup-2.yaml"
 
 data SetupOpts = SetupOpts
-  { installIfMissing :: !Bool
+  { installGhcIfMissing :: !Bool
+  , installMsysIfMissing :: !Bool
   , useSystem :: !Bool
     -- ^ Should we use a system compiler installation, if available?
   , wantedCompiler :: !WantedCompiler
@@ -661,7 +662,8 @@ setupEnv needTargets buildOptsCLI mResolveMissingGHC = do
   actual <- either throwIO pure $ wantedToActual wcVersion
   let wc = actual^.whichCompilerL
       sopts = SetupOpts
-        { installIfMissing = config.installGHC
+        { installGhcIfMissing = config.installGHC
+        , installMsysIfMissing = config.installMsys
         , useSystem = config.systemGHC
         , wantedCompiler = wcVersion
         , compilerCheck = config.compilerCheck
@@ -1120,7 +1122,7 @@ ensureMsys sopts getSetupInfo' = do
       case getInstalledTool installed (mkPackageName "msys2") (const True) of
         Just tool -> pure (Just tool)
         Nothing
-          | sopts.installIfMissing -> do
+          | sopts.installMsysIfMissing -> do
               si <- runMemoized getSetupInfo'
               let msysDir = fillSep
                     [ style Dir "msys2-yyyymmdd"
@@ -1185,7 +1187,7 @@ installGhcBindist sopts getSetupInfo' installed = do
   case existingCompilers of
     (tool, build_):_ -> pure (tool, build_)
     []
-      | sopts.installIfMissing -> do
+      | sopts.installGhcIfMissing -> do
           si <- runMemoized getSetupInfo'
           downloadAndInstallPossibleCompilers
             (map snd possibleCompilers)

src/Stack/SetupCmd.hs

@@ -38,33 +38,50 @@ data SetupCmdOpts = SetupCmdOpts
 setupCmd :: SetupCmdOpts -> RIO Runner ()
 setupCmd sco = withConfig YesReexec $ do
   installGHC <- view $ configL . to (.installGHC)
-  if installGHC
-    then
-       withBuildConfig $ do
-       (wantedCompiler, compilerCheck, mConfigFile) <-
-         case sco.compilerVersion of
-           Just v -> pure (v, MatchMinor, Nothing)
-           Nothing -> do
-            wantedCompilerVersion <- view wantedCompilerVersionL
-            compilerCheck <- view (configL . to (.compilerCheck))
-            configFile <- view configFileL
-            -- We are indifferent as to whether the configuration file is a
-            -- user-specific global or a project-level one.
-            let eitherConfigFile = EE.fromEither configFile
-            pure
-              ( wantedCompilerVersion
-              , compilerCheck
-              , Just eitherConfigFile
-              )
-       setup sco wantedCompiler compilerCheck mConfigFile
-    else
-      prettyWarnL
-        [ "The"
-        , style Shell "--no-install-ghc"
-        , flow "flag is inconsistent with"
-        , style Shell (flow "stack setup") <> "."
-        , flow "No action taken."
-        ]
+  installMsys <- view $ configL . to (.installMsys)
+  case (installGHC, installMsys) of
+    (True, True) -> withBuildConfig $ do
+      (wantedCompiler, compilerCheck, mConfigFile) <-
+        case sco.compilerVersion of
+          Just v -> pure (v, MatchMinor, Nothing)
+          Nothing -> do
+           wantedCompilerVersion <- view wantedCompilerVersionL
+           compilerCheck <- view (configL . to (.compilerCheck))
+           configFile <- view configFileL
+           -- We are indifferent as to whether the configuration file is a
+           -- user-specific global or a project-level one.
+           let eitherConfigFile = EE.fromEither configFile
+           pure
+             ( wantedCompilerVersion
+             , compilerCheck
+             , Just eitherConfigFile
+             )
+      setup sco wantedCompiler compilerCheck mConfigFile
+    (False, True) -> warn
+      [ styledNoInstallGHC
+      , singleFlag
+      ]
+    (True, False) -> warn
+      [ styledNoInstallMsys
+      , singleFlag
+      ]
+    (False, False) -> warn
+      [ styledNoInstallGHC
+      , "and"
+      , styledNoInstallMsys
+      , flow "flags are"
+      ]
+ where
+  styledNoInstallGHC = style Shell "--no-install-ghc"
+  styledNoInstallMsys = style Shell "--no-install-msys"
+  singleFlag = flow "flag is"
+  warn docs = prettyWarnL $
+       ["The"]
+    <> docs
+    <> [ flow "inconsistent with"
+       , style Shell (flow "stack setup") <> "."
+       , flow "No action taken."
+       ]
 
 setup ::
      (HasBuildConfig env, HasGHCVariant env)
@@ -78,7 +95,8 @@ setup ::
 setup sco wantedCompiler compilerCheck configFile = do
   config <- view configL
   sandboxedGhc <- (.sandboxed) . fst <$> ensureCompilerAndMsys SetupOpts
-    { installIfMissing = True
+    { installGhcIfMissing = True
+    , installMsysIfMissing = True
     , useSystem = config.systemGHC && not sco.forceReinstall
     , wantedCompiler
     , compilerCheck

src/Stack/Types/Config.hs

@@ -97,6 +97,9 @@ data Config = Config
   , installGHC              :: !Bool
     -- ^ Should we automatically install GHC if missing or the wrong
     -- version is available? Can be overridden by command line options.
+  , installMsys              :: !Bool
+    -- ^ On Windows, should we automatically install MSYS2 if missing? Can be
+    -- overridden by command line options.
   , skipGHCCheck            :: !Bool
     -- ^ Don't bother checking the GHC version or architecture.
   , skipMsys                :: !Bool