> Out of curiosity, what happens when you add two more flags: --cpu:amd64 and > --os:windows?
Very strange, that makes it use gcc instead of mingw (although I specified the d:mingw option) which doesn't work of course. The errors shown are that it can't find io.h and windows.h, but the last line says: Error: execution of an external compiler program 'gcc -c -w -fmax-errors=3 -mno-ms-bitfields -march=x86-64 -mtune=generic -O2 -pipe -fno-plt -fexceptions -Wp,-D_FORTIFY_SOURCE=2 -Wformat -Werror=format-security -fstack-clash-protection -fcf-protection -DWIN32_LEAN_AND_MEAN -I/usr/lib/nim/lib -I/home/dirk/projects/nim-opengl -o /home/dirk/.cache/nim/main_d/@m..@s..@s..@s..@susr@slib@snim@s...@ssyncio.nim.c.o /home/dirk/.cache/nim/main_d/@m..@s..@s..@s..@susr@slib@snim@s...@ssyncio.nim.c' failed with exit code: 1 Run