Changelogs for 3.12.1.0

Author: geekosaur

changelog.d/issue-10042

@@ -0,0 +1,45 @@
+Cabal and Cabal-syntax 3.12.1.0 changelog and release notes
+---
+
+
+### Significant changes
+
+- Update ghc args normalization and ghc option 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.
+
+- Add mhs as a known Haskell compiler [#9878](https://github.com/haskell/cabal/pull/9878)
+
+  This simply add MHS to the enumeration of known Haskell compilers.
+
+- 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.
+
+### 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/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.

changelog.d/issue-10063

@@ -283,7 +283,7 @@ This file will be edited and the changes incorprated into the official
 
   This flag gives the user full control over the directory where the documentation is placed. It allows both relative and absolute paths.
 
-- Remove useles "Log" log level [#9151](https://github.com/haskell/cabal/issues/9151) [#9346](https://github.com/haskell/cabal/pull/9346)
+- Remove useless "Log" log level [#9151](https://github.com/haskell/cabal/issues/9151) [#9346](https://github.com/haskell/cabal/pull/9346)
 
     - Remove "Log" as a log level in favour of "Info".
     - Remove "Show" in Severity and replace by "displaySeverity" function
@@ -341,3 +341,30 @@ This file will be edited and the changes incorprated into the official
 
     The "Executing·install·plan··serially" and other similar "Executing
     install plan··..." outputs no longer contain double spaces.
+
+- External commands now propagate exit code from child process [#10063](https://github.com/haskell/cabal/issues/10063) [#10100](https://github.com/haskell/cabal/pull/10100)
+
+  The exit code from an external command is now propagated as the exit code of
+  cabal-install when invoked by calling an external command.
+
+  For example, if your external command exits with code 1, then cabal-install will
+  also exit with code 1.
+
+  This mechanism can be used by an external command to signal failure.
+
+- Allow whitespace in targets [#8875](https://github.com/haskell/cabal/issues/8875) [#10032](https://github.com/haskell/cabal/pull/10032)
+
+  Allow spaces in the final component of target selectors. This resolves an issue
+  where using absolute paths in selectors can fail if there is whitespace in the
+  parent directories of the project.
+
+- Fix --program-suffix resulting in invalid installation [#8823](https://github.com/haskell/cabal/issues/8823) [#9919](https://github.com/haskell/cabal/issues/9919) [#10056](https://github.com/haskell/cabal/pull/10056)
+
+- Renders project configuration provenance as a list of canonical paths [#9971](https://github.com/haskell/cabal/issues/9971) [#9985](https://github.com/haskell/cabal/pull/9985)
+
+  Removes interleaved rendering of project imports.
+
+- Abbreviate solver rejection messages with installed versions [#9823](https://github.com/haskell/cabal/issues/9823) [#9824](https://github.com/haskell/cabal/pull/9824)
+
+  Abbreviate solver rejection messages even in the presence of installed versions.
+