The packages in the msys2 repository (which, if they link to msys-2.0.dll are all GPL licensed) only really exist to aid building the packages in the mingw32 and mingw64 repositories which don't implement fork() at all and are the real purpose of MSYS2, i.e. providing normal Windows software.
https://www.cygwin.com/faq.html#faq.api.fork
The packages in the msys2 repository (which, if they link to msys-2.0.dll are all GPL licensed) only really exist to aid building the packages in the mingw32 and mingw64 repositories which don't implement fork() at all and are the real purpose of MSYS2, i.e. providing normal Windows software.
If you want a POSIX-y system, please use Cygwin.