https://issues.dlang.org/show_bug.cgi?id=15538 --- Comment #8 from Johannes Loher <johannes.loher at fg4f.de> --- I tracked this down a bit. It worked fine till 2.063.2 (including). From 2.064 onward it sarts to segfault. Finally, from 2.068 onward, the assert error starts hppening. --