On 03.01.2016 21:32, TheDGuy wrote: > If i type: > gcc -c -otest.c.o > > the 'test.c.o' file is generated but if i type: > > dmd main.d test.c.o i get: 'Error: unrecognized file extension o'? You're probably on Windows then? dmd doesn't recognize the .o extension on Windows, use .obj instead.