Am 09.10.2014 17:39, schrieb Mickaël Bouchaud: 

Undefined symbols for architecture x86_64:
   "_D4core6thread5Fiber4callMFbZC6Object", referenced from:
       _D4vibe4core4core14VibeDriverCore14resumeCoreTaskMFC4vibe4core4core8CoreTaskC9ExceptionZv in libvibe-d.a(core_32c2_57b.o)
   "_D4core6thread6Thread7getThisFZC4core6thread6Thread", referenced from:
       _D4vibe4core3log6rawLogFNbNfAyaiE4vibe4core3log8LogLevelAyaZ9__lambda6FNeZC4core6thread6Thread in libvibe-d.a(log_343e_26c.o)
       _D4vibe4core4core18_sharedStaticCtor1FZv in libvibe-d.a(core.o)
       _D4vibe4core4core12_staticCtor3FZv in libvibe-d.a(core.o)
       _D4vibe4core4core12_staticDtor4FZv in libvibe-d.a(core.o)
       _D4vibe4core4core14VibeDriverCore14resumeCoreTaskMFC4vibe4core4core8CoreTaskC9ExceptionZv in libvibe-d.a(core_32c2_57b.o)
       _D4vibe4core4core17handleWorkerTasksFZv in libvibe-d.a(core_32ca_6ec.o)
       _D4vibe4core4core8CoreTask4joinMFZv in libvibe-d.a(core_32c1_31c.o)
       ...
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
--- errorlevel 1

That looks strange, those should be standard Phobos symbols.
Unfortunately I don't have a Mac available for testing until next week.
I'll see if I can reproduce the issue then.

As a complete shot in the dark, you could try to add "libs": <br>["phobos2"] to the dub.json of the "testdouble" package. As a sanity
check, does invoking dmd on the following produce any errors? 

import core.thread;
void main()
{
	auto t = Thread.getThis();
	auto f = new Fiber({});
	f.call();
}