https://issues.dlang.org/show_bug.cgi?id=12848
--- Comment #1 from Martin Krejcirik <m...@krej.cz> --- https://github.com/D-Programming-Language/druntime/blob/master/src/rt/dmain2.d#L303 Actually this assert fails, because argc contains wrong number of arguments (wargc is right). argc is set before C main(), where startup code calls GetCommandLineA and then _setargv, which fails to recognize correctly number of arguments. Also argv string is in the Windows charset at this stage. So the solution seem to be either to fix the startup code or to "fix" argc and argv later using windows API W functions. --