I will add my woes to this small group of unfortunates. I trying to use the OF 0.9.8 for msys2 on windows 10. i followed the directions on the msys2 setup page and got as far as compiling the libraries. my install of msys2 did not have mingw32_shell.bat so i ran "C:\msys64\msys2_shell.cmd -mingw32".
when i ran make in the project directory it returned the same error Guillaume is getting..
I've been trying to puzzle through config_share,mk file. i did notice that when i ran 'uname -s' from a shell, it returns MSYS_NT-10.0 and msys2 shell returns MINGW32_NT-10.0. i have no clue if that is significant.
looking further at config_share.mk, it says:
else ifneq (,$(findstring MINGW32_NT,$(PLATFORM_OS)))
else ifneq (,$(findstring MSYS_NT,$(PLATFORM_OS)))
else ifneq (,$(findstring MINGW64_NT,$(PLATFORM_OS)))
so it should be catching either of those values, and there is a msys2 directory inside the project directory.