dmd only compiles in the files you actually pass to it. rdmd
will try to find the required files automatically.
Since you didn't pass the file with the function to dmd, it
knows it exists, but leaves it out of the final link (it
assumes it might come from a library or something). That's why
you see the error.
Ah ok, I understand. So calling with "dmd Special/special.d
Common/common.d" works.
But when I compile common.d to common.o (with dmd -c common.d)
and remove common.d after that is there still a possibility to
link? The obvious doesn't work:
$> dmd Special/special.d Common/common.o Special/special.d(4):
Error: module common is in file 'common.d' which cannot be read
import path[0] = /usr/include/dmd/phobos
import path[1] = /usr/include/dmd/druntime/import
