GHC 9.12.4-rc1 is now available

I second @hasufell’s appeal for more eyes on the RC releases. If you want to use with Stack:

Add a setup-info dictionary to a configuration file with the applicable entry for your operating system. For example, on Windows or macOS/AArch64, a stack.yaml:

snapshot: nightly-2026-03-13 # GHC 9.12.3
compiler: ghc-9.12.3.20260311
compiler-check: match-exact # Anticipating future rc releases

# Only required before the GHC version has been installed:
setup-info:
  ghc:
    windows64:
      9.12.3.20260311:
        url: https://downloads.haskell.org/ghc/9.12.4-rc1/ghc-9.12.3.20260311-x86_64-unknown-mingw32.tar.xz
        # Can be extended with SHA protections etc: see https://docs.haskellstack.org/en/stable/configure/yaml/non-project/#setup-info
    macosx-aarch64:
      9.12.3.20260311:
        url: https://downloads.haskell.org/ghc/9.12.4-rc1/ghc-9.12.3.20260311-aarch64-apple-darwin.tar.bz2
        # Can be extended with SHA protections etc: see https://docs.haskellstack.org/en/stable/configure/yaml/non-project/#setup-info