I am assuming you would like to have GDC available in the MSYS2
[MINGW32 , MINGW64, and UCRT64
environments](https://www.msys2.org/docs/environments/) (which is
what I wanted). They have an open issue in the [MINGW packages
repository](https://github.com/msys2/MINGW-packages/issues/6806)
for adding support for GDC that demonstrates interest in making
this happen.
I looked into fixing the
[issue](https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104654) that
I ran into when the configure flags set the threading model to
posix threading and determined that I will not be able to fix the
issue (at least with my current knowledge). At the minimum you
would have to modify two files to add different versions of posix
code for
[MinGW](https://dlang.org/spec/version.html#predefined-versions)
in the druntime:
-
https://github.com/dlang/dmd/blob/master/druntime/src/core/sys/posix/sys/types.d
-
https://github.com/dlang/dmd/blob/master/druntime/src/core/sys/posix/pthread.d
There are more than a dozen instances of conditional compilation
related to posix threading for different posix-based
environments. This problem could be worse if the three different
MSYS2 environments need different conditional code compilation
paths (hopefully they don't). This is also made more difficult
since these files have been modified since the GCC version 11.3.0
release so the changes would have to be done against the recent
version as well as the GCC 11.3.0 version (I am assuming that the
GCC 11.3.0 GCC Version is needed to bootstrap the GDC in version
12+ of GCC).
Based on this
[comment](https://github.com/dlang/druntime/pull/3684#issuecomment-1017038399) I saw when looking at the changes to the files mentioned earlier, there is a possibility of the files being auto-generated during the build process in the future. Hopefully this issue will be resolved through auto-generation.
