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

[Arash Esbati]

Bruno Haible via "Emacs development discussions." <emacs-devel@gnu.org> writes:

> Also, the --build=x86_64-pc-cygwin option may be wrong, since you
> are on MSYS2, not on Cygwin, and there are some differences
> between both environments.

Apologies if my comment is off, I currently don't have access to a MSYS2
installation and can't say if this is already implemented, but
x86_64-pc-cygwin seems to be the future[1]:

  2025-02-14 - Moving MSYS(2) closer to Cygwin

  In MSYS2, in addition to the native environments such as
  UCRT64/CLANG64, there is also the "MSYS" environment, which contains
  mostly Cygwin-based software. Since the start of the MSYS2 project,
  the Cygwin tools in MSYS have been modified to build for MSYS instead
  of Cygwin. This means that the languages and tools have been patched
  to report their platform as "msys", and for the build tools this means
  that we have our own MSYS specific target triplet (x86_64-pc-msys),
  and uname reports "MSYS" as well. [...]
  
  Some time ago we started to remove these differences by replacing
  "msys" with "cygwin" + patches where possible. So instead of MSYS
  being a fork of Cygwin, it would just be a slightly modified/extended
  variant of Cygwin. [...]

  The next planned steps for this transition are currently:
  • Change the default host triplet from "x86_64-pc-msys" to
    "x86_64-pc-cygwin"
  • Change the runtime to be a superset of Cygwin in more places,
    e.g. make the CYGWIN env var work as a fallback if MSYS is not
    set. The goal is to make the Cygwin documentation mostly applicable
    to MSYS2 as well.

Best, Arash

Footnotes:
[1]  https://www.msys2.org/news/#2025-02-14-moving-msys2-closer-to-cygwin