> https://fedoraproject.org/wiki/Changes/F37MingwUCRT
>
> Since mingw-*.spec are very repetitive and cumbersome to modify (each
> mingw32, mingw64, ucrt package has to be defined manually, and this is
> tedious and error-prone), a custom MinGW/Fedora tool or solution will
> be proposed. In the meantime, packages can be modified to add manually
> the new target.

I think this is an important point. If this is to be done manually,
the transition will take forever and will consume a lot of maintainer
resources. I would very much encourage you do first develop macroification
to make the new subpackages easy to add. And once that is done, do spec
file munging semi-automatically, like it was done when we were renaming
python2 subpackages. (This was similar, because we needed to add a new %package
section and related sections.) Once the whole thing is ready, use a provenpackager
to update and build all packages. In my exprience, it is also important to
ask maintainers to *not* do manual conversions, because if you add automatization
later on, manually converted packages end up being a bit different and in the end
are more trouble than running the automatic converted over a few additional
files.

If that'd be helpful, I can dig up the scripts for python2. I'd be happy to help
with building scripts to do the conversion here, though I know almost nil about
mingw.