The behavoir of altering @INC when current directory is an installation
root of a module made here:
https://metacpan.org/source/MALLEN/Pod-Perldoc-3.17/lib/Pod/Perldoc.pm#L1649
should be documented in the module's pod, somehow.
This behavior is extremely useful, particularly when after:
cpanm --look Some::New::Module
but only when you know it is there, and it is not so obvious.