GHC 9.12.4-rc1 is now available

I did an unpublished test build of Stackage Nightly with this RC1 on Linux and did not hit any problems (around 3446 packages built including many testsuites and benchmark compilations). Should be close to or slightly ahead of today’s Stackage Nightly 2026-03-22 (ghc-9.12.3) :: Stackage Server . So RC1 looks promising so far to me.

(The full curator log is about 38MB, but I could upload somewhere if needed - unfortunately I forgot to preserve the actual snapshot.yamlfile.)