W0045 - Duplicate Module

Warning

-module(my_module).
    %%  ^^^^^^^^^ warning: A module with this name exists elsewhere

Explanation

The module name is already used by another module in the same project.

Only one file can own a given name, so the rest are dropped from the project's module index. Anything that resolves a module by name — navigation, references, and whole-project analyses — then sees the surviving file only, and the dropped files are analysed with less information than they should be. Renaming one of the modules is the fix.

This applies to Common Test suites as well, including duplicates that build as separate targets and so never clash at the BEAM level.