OK, I think I figured the problem: Unicode!
I have the following repro with DMD64 D Compiler v2.068.2 on Ubuntu 15
(the default installation). If there's no ~/dmd.conf, running 'dmd'
alone displays the options.
If there's a zero byte dmd.conf, things still work.
If there's a dmd.conf in Unicode format (I suspect with the two
signature bytes), dmd crashes with:
dmd: inifile.c:141: void writeToEnv(StringTable*, char*): Assertion `p'
failed.
This was caused by the MonoDevelop editor, which saves files in the
format. Emacs also happily loads these files and signals the format with
a "U" in the status bar.
Andrei
