I am getting the following error calling watchDirectory for the following program. On mac osx mavericks. Any help is appreciated, thanks.

The log output

starting watch
CoreTaskFiber was terminated unexpectedly: Assertion failure

Here is the program

import vibe.d;

shared static this()
{

runTask({
	logInfo("starting watch");
	auto dw = watchDirectory("/Users/glen/_a/");
	logInfo("watching");
});

}