On Feb 26, 2019, at 13:23, Ivan Pozdeev <report@bugs.python.org> wrote:
> 
> Easy. Insert a chunk into site.py that would call pdb.set_trace() if an envvar (e.g. `PYSITEDEBUG') or a command line switch is set.
> 
> Actually, why can't whoever has this problem add such a chunk themselves? Is this really such a frequent and ubiquitous problem
> that this needs to be in the stock codebase? I suspect we're dealing with a vocal minority here.

Basically yes, I’ve done this.  But think of the poor user who doesn’t have that expertise or ability to hack on an installed Python’s site.py file.  When their application breaks because some faulty pth was installed behind their back, how do they debug their application when the breakage has already occurred before Python even gets to their code?  How do they answer questions like “where did that magical sys.path entry come from?” or “how did that module get in sys.modules already?”