Issue #21286 has been updated by alanwu (Alan Wu). I sent https://github.com/ruby/ruby/pull/13202 which I believe should fix compatibility with GCC 15 on MinGW (it passed CI with `-std=c23` on GCC 14). Is there a way to explicitly pick GCC 15 on CI with setup-ruby?
We don't know if this is a Windows only issue or if this is an issue with all OS's using gcc.
It's a bit of both, but Windows gets more exposure. See #21293 ---------------------------------------- Bug #21286: Windows - MSYS2 just updated to GCC 15.1.0, builds failing https://bugs.ruby-lang.org/issues/21286#change-112828 * Author: MSP-Greg (Greg L) * Status: Open * ruby -v: master * Backport: 3.2: UNKNOWN, 3.3: UNKNOWN, 3.4: UNKNOWN ---------------------------------------- MSYS2 just updated to GCC 15.1.0, and the ruby-loco builds failed to compile. See [MinGW](https://github.com/MSP-Greg/ruby-loco/actions/runs/14693708990/job/412325097...) & [UCRT](https://github.com/MSP-Greg/ruby-loco/actions/runs/14693775816/job/412326620...) Also, I compiled mswin locally with the recent VS 'preview' release, and the bug has been fixed. -- https://bugs.ruby-lang.org/