well, not quite, or it’s wrong (i wont even watch it)
using mingw, you need to disable MSMF related code (no support for that in mingw): in cmake:
WITH_MSMF=OFF
WITH_OBSSENSOR=OFF
clean build folder (start from scratch w. cmake) and rerun
(i also think, you got the wrong mingw, it might lack support for posix threads / mutex, but idk this one…)
please also take a look, which libpython version is shipped with your mingw (maybe you can only link against python3.8)