The new Release 20.03 is out! You can download binaries for Windows and many major Linux distros here .
lib\gcc_lib\libwxmsw28u.a(monolib_regex.o):regex.cpp:(.text+0x84)||undefined reference to `_wx_regfree'|...mingw32-make -f makefile.gcc USE_XRC=1 SHARED=0 MONOLITHIC=1 BUILD=release UNICODE=0