Tim, looks like
clean did not worked well for me. So I have created a mess by either skipping clean and using other options, or I can blame clean...
So, I have deleted wxWidgets, downloaded a new one and in a processed of building it, on my machine it is 30 min or so ....
wxWidgets is being built with:
mingw32-make -f makefile.gcc MONOLITHIC=1 SHARED=1 UNICODE=1 BUILD=release TARGET_CPU=X64 CXXFLAGS="-std=gnu++11"
btw, building wxW.. with Mingw I have had first to fix filectrlg.cpp,
../../src/generic/filectrlg.cpp:235:35: error: 'S_IFDIR' was not declared in this scope
m_type |= (buff.st_mode & S_IFDIR) != 0 ? is_dir : 0;
Fix #define S_IFDIR 0040000 /* Directory */
UPDATE: problem solved! wxWidets 3.0.0 now compiles without problems! thank you for the help.