Thanks for the feedback, I thought it might be a long shot. I will go back to removing the *use* of the feature everywhere I can find it, since it is so problematic and rarely, if ever, desirable.

> it's an essential feature that has been documented for a very long time
> https://docs.python.org/3.5/library/site.html

The entirety of the documentation of this feature appears to be this sentence on that page:

> Lines starting with import (followed by space or tab) are executed.

No explanation or examples are given, nor any reasoning about the feature or why one might use it.

> This change will basically break all Python applications

This surprises me. Can you elaborate? I have not seen an application rely on executing code in .pth files.

> If you believe that we can smoothly move to a world without .pth files, 
> you should propose an overall plan, step by step.

I have no desire to remove .pth files. .pth files are a fine way to add locations to sys.path. It's .pth files *executing arbitrary code* that's the problem, very surprising, and a source of many errors (especially how it is used in setuptools).