On Sunday, 9 September 2018 at 04:32:32 UTC, Jonathan Marler- The .d extension is not implied, like for dmd/rdmdI haven't come up with any reasons to support this. Maybe you can enlighten me?"rund prog" is shorter and easier to type than "rund prog.d".
Support main source with no extension: https://github.com/marler8997/rund/pull/1