Segmentation faults in profiled way
It seems that profiling has regressed sometime between GHC 8.0 and 8.2. A few times since September I have noticed that profiled programs (in particular, GHC itself built with profiling enabled) seem to segmentation fault.
This most recent case was produced by building commit 6ebfbdfb with the following in
BuildFlavour = prof define add_mods_flag = $(foreach mod,$(2),$(eval $(basename $(mod))_HC_OPTS += $(1))) endef $(call add_mods_flag,-fprof-auto,$(wildcard compiler/typecheck/*.hs)) STRIP_CMD = :
and using the resulting stage2 compiler to bootstrap the same commit. Eventually the build will fail with a segmentation fault. Unfortunately it seems the crash isn't entirely reproducible.