Changelogs for 3.12.1.0

release-notes/Cabal-3.12.0.0.md

@@ -55,7 +55,7 @@ Cabal and Cabal-syntax 3.12.0.0 changelog and release notes
       `filterPackageChecksById`, this can be used by third-party
       tools to filter warnings.
 
-- Add support for `GHC2024` [#9736](https://github.com/haskell/cabal/issues/9736)
+- Add support for `GHC2024` [#9736](https://github.com/haskell/cabal/issues/9736) [#9791](https://github.com/haskell/cabal/pull/9791)
 
   Support for the `GHC2024` language edition, introduced by GHC 9.10, has been
   added. It can now be used in the `default-language` and `other-languages`
@@ -73,14 +73,18 @@ Cabal and Cabal-syntax 3.12.0.0 changelog and release notes
   If you are dealing with a custom setup, you have to invoke
   `./Setup repl --repl-multi-file`.
 
+- Label error messages with codes (following GHC, Stack)
+
+    As with GHC and Stack, Cabal and cabal-install now generate warnings and errors prefixed with error codes of the form `[Cabal-xxxxx]`. These will be documented on https://errors.haskell.org, although very few are as yet.
+
 ### Other changes
 
-- `cabal init` should not suggest Cabal < 2.0 [#8680](https://github.com/haskell/cabal/issues/8680)
+- `cabal init` should not suggest Cabal < 2.0 [#8680](https://github.com/haskell/cabal/issues/8680) [#8700](https://github.com/haskell/cabal/pull/8700)
 
     'cabal init' no longer suggests users to set cabal-version to less than
     2.0.
 
-- Remove Distribution.Utils.TempTestDir module from Cabal library [#9453](https://github.com/haskell/cabal/issues/9453) [#9454](https://github.com/haskell/cabal/pull/9454)
+- Remove `Distribution.Utils.TempTestDir` module from Cabal library [#9453](https://github.com/haskell/cabal/issues/9453) [#9454](https://github.com/haskell/cabal/pull/9454)
 
     This library was only used by internal tests, and now lives in the
     `Cabal-tests` library which is shared across test components.
@@ -106,7 +110,7 @@ Cabal and Cabal-syntax 3.12.0.0 changelog and release notes
 
    - `checkPackage` signature has been simplified,
      you do not need to pass a specific configuration of the package, since
-     we do not flatten GenericPackageDescription any more.
+     we do not flatten `GenericPackageDescription` any more.
    - `checkPackageFileNames` has been removed,
      use `checkPackageFiles` instead.
    - `checkPackageFilesGPD` has been introduced,

release-notes/Cabal-3.12.1.0.md

@@ -0,0 +1,54 @@
+Cabal and Cabal-syntax 3.12.1.0 changelog and release notes
+---
+
+
+### Significant changes
+
+- Update GHC arguments normalization and GHC options rendering [#9729](https://github.com/haskell/cabal/issues/9729) [#10014](https://github.com/haskell/cabal/pull/10014)
+
+  The flags `-fdiagnostics-as-json`, `-fprint-error-index-lists`, `-fbreak-points`, `-dipe-stats`, `-ffamily-application-cache`, `-fprint-redundant-promotion-ticks`, `-fshow-error-context` and `-funoptimized-core-for-interpreter` have been added to the flags that do not cause recompilation.
+
+- Warn on missing `default-language` [#9620](https://github.com/haskell/cabal/issues/9620) [#9766](https://github.com/haskell/cabal/pull/9766)
+
+  - To help the adoption of GHC language editions, `cabal check` will now
+    warn about missing `default-language`.
+
+- Add mhs as a known Haskell compiler [#9878](https://github.com/haskell/cabal/pull/9878)
+
+- Re-instate `initialBuildSteps` [#9856](https://github.com/haskell/cabal/issues/9856) [#9950](https://github.com/haskell/cabal/pull/9950)
+
+  The `initialBuildSteps` function from `Distribution.Simple.Build`, which had
+  been hastily removed, has been reinstated.
+
+  It now comes with a deprecation warning: calling that function does not suffice
+  to prepare the sources for a package, as there are other steps that one might
+  also need to perform:
+
+    - running pre-processors (such as alex/happy)
+    - running pre-build hooks or custom logic
+      (in build-type: Hooks or build-type: Custom or Configure)
+
+  Consumers wanting to prepare the sources of a package, e.g. in order to launch a
+  REPL session, are advised to run `setup repl --repl-multi-file=<fn>` instead.
+
+- Label error messages with codes (following GHC, Stack)
+
+    As with GHC and Stack, Cabal and cabal-install now generate warnings and errors prefixed with error codes of the form `[Cabal-xxxxx]`. These will be documented on https://errors.haskell.org, although very few are as yet.
+
+    This change was actually present in Cabal-3.12.0.0, but was inadvertently omitted from the changelog.
+
+### Other changes
+
+- Don't recommend deprecated/removed `extensions` field [#10042](https://github.com/haskell/cabal/issues/10042) [#10044](https://github.com/haskell/cabal/pull/10044)
+
+  When applicable, field `default-extensions` is recommended (rather than
+  deprecated/removed `extensions:`).
+
+- Make `Setup copy` and `Setup install` succeed when there's no executable or library [#6750](https://github.com/haskell/cabal/issues/6750) [#9926](https://github.com/haskell/cabal/pull/9926)
+
+  Historically the Setup copy and install steps would fail if the package didn't
+  contain an executable or library component. In this case there's nothing to do.
+
+  This required workarounds for downstream users of Cabal to handle this edge case.
+  Now that this error has been downgraded to a warning, Cabal will succeed if
+  there's nothing to do.