Something is missing or broken causing the gc to fail. A quick fix is currently in place to just use the stub gc, which is obviously inadequate.
From druntime's posix.mak:
ifeq ($(OS)$(MODEL),freebsd64)
GC_MODULES = gcstub/gc
else
GC_MODULES = gc/gc gc/gcalloc gc/gcbits gc/gcstats gc/gcx
endif
It's entirely possible that the problem lies in either dmd or druntime. For now, filed against dmd.
Comment #1 by braddr — 2011-05-22T22:19:37Z
*** This issue has been marked as a duplicate of issue 5484 ***