[Python-Dev] PEP 553; the interaction between $PYTHONBREAKPOINT and -E

[Antoine Pitrou]

On Wed, 4 Oct 2017 14:06:48 -0400
Barry Warsaw <barry at python.org> wrote:
> Victor brings up a good question in his review of the PEP 553 implementation.
> 
> https://github.com/python/cpython/pull/3355
> https://bugs.python.org/issue31353
> 
> The question is whether $PYTHONBREAKPOINT should be ignored if -E is given?
> 
> I think it makes sense for $PYTHONBREAKPOINT to be sensitive to -E, but in thinking about it some more, it might make better sense for the semantics to be that when -E is given, we treat it like PYTHONBREAKPOINT=0, i.e. disable the breakpoint, rather than fallback to the `pdb.set_trace` default.

"""Special cases aren't special enough to break the rules."""

People expect -E to disable envvar-driven overrides, so just treat it
like that and don't try to second-guess the user.

Regards

Antoine.