>>the OP ... decided to rename not just the package -- which can be called >>anything, ... and the handler() function, which would be a mistake, because it >>MUST be called handler() for the module to work.
I agree that he should have named it handler() for it to work with the configuration and suggested changes to it. But it is NOT required to name the handler routine "handler()". It can be called anything. To make the OP's handler work, something like the following directive would be needed:
Since I didn't point that out, that part of my response was more of a distraction than solution, and yours a significant step toward a solution.