On Mon, 13 May 2019 16:27:35 +0200, Sönke Ludwig wrote:

It used to be the case that accessing files within sub directories of
directories specified by -J was explicitly disallowed in the compiler.
However, it appears that people were able to change Walter's mind and
the behavior got revised in 2016:
dmd#5337.

I don't remember which limitations DUB and/or diet-ng have inherited
from the old DMD restriction, but I'll look into it ASAP.

Great. Making organization independent of code is very handy.