This module has the same pitfall like Test::NoWarnings had - it will get tripped up by a working-but-warning-spewing dependency. Would you consider enhancements to analyze the caller() on every trapped warning and pass-through anything that was not emitted from t/ lib/, etc (similar heuristics to strictures.pm)
With an option to disable that, sure. I could imagine that some people
might want to be brutal and fail even warnings from dependencies.
But the default could be smart.
I've added this in 0.002