Seemingly patternless optlink premature termination

[pineapple via Digitalmars-d]

On Sunday, 8 January 2017 at 14:15:26 UTC, pineapple wrote:
> I'm working on my dumb library and I have run into a case where 
> when I add this line to a module, I get an optlink error 
> attempting to compile it:
>
>     unittest{}

After deciding to let my inability to add some unit tests to that 
module I started working on some other code in the same project. 
At this point it seems completely arbitrary which lines produce 
optlink errors. Since the `unittest{}` issue I have, in other 
modules, had optlink errors occur depending on the presence of 
arbitrary method and function calls, too.