Re: Failure building Emacs master on MSYS2 [MSYS2 PKG]

[Collin Funk]

Hi Bruno,

Thanks for re-linking the reference to the "Moving MSYS(2) closer to
Cygwin" document. I missed it while skimming through the thread...

> And in this case, Collin was kind enough to provide the analysis for the
> MSYS people [1]. Namely, all the MSYS people need to do here is to upgrade
> their GCC to version 13.4, 14.3, or 15.1. [2]

Yep, that should fix it.

Just to avoid any suprises, MSYS2 with a fixed GCC will fail until Emacs
gets an update from Gnulib. Emacs m4/stddef_h.m4 has:

    AC_CACHE_CHECK([whether <stddef.h> is idempotent],
      [gl_cv_stddef_idempotent],
      [AC_COMPILE_IFELSE([AC_LANG_SOURCE(
         [[
         #if __GNUC__ == 13 || __GNUC__ == 14
          #error "bug 114870 is present"
         #endif
         ]])],
         [gl_cv_stddef_idempotent="guessing yes"],
         [gl_cv_stddef_idempotent="guessing no"])
      ])

This file was updated in Gnulib to account for the minor version fixes
after it was last merged into Emacs:

    AC_CACHE_CHECK([whether <stddef.h> is idempotent],
      [gl_cv_stddef_idempotent],
      [AC_COMPILE_IFELSE([AC_LANG_SOURCE(
         [[
         #if \
             ((__GNUC__ == 13 && __GNUC_MINOR__ <= 3) \
              || (__GNUC__ == 14 && __GNUC_MINOR__ <= 2))
          #error "bug 114870 is present"
         #endif
         ]])],
         [gl_cv_stddef_idempotent="guessing yes"],
         [gl_cv_stddef_idempotent="guessing no"])

I will let Eli and Paul decide if ./admin/merge-gnulib can be done.
Since I know Emacs tries to avoid it near releases and I am not familiar
with the release schedule (Emacs 30 feels recent though).

Collin