Issue #21286 has been updated by mdalessio (Mike Dalessio). I wonder if `-Werror` is being set implicitly? I'm seeing similar failures up and down my CI pipelines for the gems mentioned by @Earlopain, in addition to libxml2 compilation in Nokogiri's upstream integration testing. ---------------------------------------- Bug #21286: Windows - MSYS2 just updated to GCC 15.1.0, builds failing https://bugs.ruby-lang.org/issues/21286#change-112810 * 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/