https://issues.dlang.org/show_bug.cgi?id=18544
--- Comment #2 from Steven Schveighoffer <schvei...@yahoo.com> --- Hm.. actually that doesn't work, because one thread could be adding roots while the other one is initializing the GC, causing a race. There may just have to be some sort of lock, even if it's a simple/spin lock. --