Unittest hangs on completion

[Steven Schveighoffer via Digitalmars-d-learn]

On 12/29/16 3:27 PM, David Zhang wrote:
> Hi,
>
> I've noticed recently, that whenever I unittest, it program hangs either
> at the very end, or right before they start. When using vanilla unit
> tests, the program appears to hang after the "All unit tests have been
> completed successfully." message, and I have to force to program to
> exit. However, when I use unit-threaded for my unit testing, it gets to
> the "Running unit tests in dirs ["."]" and then refuses to do anything
> more. Strangely enough, sometimes commenting out one or two tests seems
> to fix the issue with unit-threaded, only to resurface when I write a
> new test. Just what is going on?

Where does the "All unit tests have been completed successfully." 
message come from? That's not standard D, which prints nothing.

-Steve