Haskell: GHC 9.12.3 is now available

NewsBot · 27 December 2025 13:26

A new Haskell blog post/announcement has been posted!

GHC 9.12.3 is now available

zubin - 2025-12-27

The GHC developers are very pleased to announce the release of GHC 9.12.3. Binary distributions, source distributions, and documentation are available at downloads.haskell.org.

GHC 9.12.3 is a bug-fix release fixing many issues of a variety of severities and scopes, including:

Fix a number of crashes and miscompilations in the compiler frontend (#25004, #25960, #26256)

Improvements to efficiency of the runtime linker (#26009)

Fixes for several bugs in bytecode generation and the bytecode interpreter (#23210, #25975, #25750)

Fixes for bugs in the handling of WHITEHOLEs in the RTS (#26204, #26205)

Fix incorrect code generation for SSE vector operations (#25859)

Fix a use-after-free in the Windows runtime linker (#26613)

Support for synchronous JSFFI exports for the wasm backend

And many more!

A full accounting of these fixes can be found in the release notes. As always, GHC’s release status, including planned future releases, can be found on the GHC Wiki http://haskell.org/ghc/blog/20251227-ghc-9.12.3-released.html