Merge pull request #6679 from commercialhaskell/fix6678

Fix #6678 Add Cabal boot package to `setup-depends` deps, when needed

.stan.toml

@@ -72,14 +72,14 @@
 
 # Anti-pattern: Data.ByteString.Char8.pack
 [[ignore]]
-  id = "OBS-STAN-0203-erw24B-1031:3"
+  id = "OBS-STAN-0203-erw24B-1039:3"
 # ✦ Description:   Usage of 'pack' function that doesn't handle Unicode characters
 # ✦ Category:      #AntiPattern
 # ✦ File:          src\Stack\Build\ExecuteEnv.hs
 #
-#  1030 ┃
-#  1031 ┃   S8.pack . formatTime defaultTimeLocale "%Y-%m-%dT%H:%M:%S%6Q"
-#  1032 ┃   ^^^^^^^
+#  1038 ┃
+#  1039 ┃   S8.pack . formatTime defaultTimeLocale "%Y-%m-%dT%H:%M:%S%6Q"
+#  1040 ┃   ^^^^^^^
 
 # Anti-pattern: Data.ByteString.Char8.pack
 [[ignore]]

ChangeLog.md

@@ -14,6 +14,10 @@ Behavior changes:
   (Latin-1) character in Stack's 'programs' path, as `hsc2hs` does not work if
   there is such a character in the path to its default template
   `template-hsc.h`.
+* Stack customizes setup using `Cabal`, so if a `setup-depends` field does not
+  mention it as a dependency, Stack warns and adds the GHC boot package as a
+  dependency. Previously, Stack would not do so but only warn that build errors
+  were likely.
 
 Other enhancements:
 

doc/commands/build_command.md

@@ -213,8 +213,7 @@ information about how these dependencies get specified.
 If a package description specifies a custom build type, it must also specify a
 custom setup. That should list the dependencies needed to compile `Setup.hs`.
 Stack further customises the setup, using the `Cabal` package. If that package
-is not listed, Stack will not add the package as a dependency but warn that
-build errors are likely.
+is not listed, Stack will warn and add the GHC boot package as a dependency. 
 
 In addition to specifying targets, you can also control what gets built, or
 retained, with the flags and options listed below. You can also affect what gets

src/Stack/Build/ExecuteEnv.hs

@@ -729,13 +729,21 @@ withSingleContext
               -- providing an explicit list of dependencies, and we should
               -- simply use all of them.
               Just customSetupDeps -> do
-                unless (Map.member (mkPackageName "Cabal") customSetupDeps) $
-                  prettyWarnL
-                    [ fromPackageName package.name
-                    , flow "has a setup-depends field, but it does not mention \
-                           \a Cabal dependency. This is likely to cause build \
-                           \errors."
-                    ]
+                cabalPackageArg' <-
+                  if Map.member (mkPackageName "Cabal") customSetupDeps
+                    then pure []
+                    else do
+                      prettyWarnL
+                        [ style Current (fromPackageName package.name)
+                        , flow "has a"
+                        , style Shell "setup-depends"
+                        , flow "field, but it does not mention a"
+                        , style Current "Cabal"
+                        , flow "dependency. Stack customizes setup using \
+                               \Cabal, so it has added the GHC boot package as \
+                               \a dependency."
+                        ]
+                      pure cabalPackageArg
                 matchedDeps <-
                   forM (Map.toList customSetupDeps) $ \(name, depValue) -> do
                     let matches (PackageIdentifier name' version) =
@@ -772,7 +780,7 @@ withSingleContext
                           )
                       )
                   )
-                pure (packageDBArgs ++ depsArgs ++ cppArgs)
+                pure (packageDBArgs ++ depsArgs ++ cabalPackageArg' ++ cppArgs)
 
               -- This branch is usually taken for builds, and is always taken
               -- for `stack sdist`.