[Distutils] setup.py install using pip

[Paul Moore]

On 7 December 2015 at 18:58, Erik Bray <erik.m.bray at gmail.com> wrote:
> I wasn't able to produce this problem.  Even with --no-binary
> specified pip installs (by default) with
> --single-version-externally-managed.  My prototype implicitly disables
> the --pip flag if --single-version-externally-managed was specified
> (true to the purpose of that flag).

Ah - that was the bit I was missing, the
--single-version-externally-managed flag can be used to trigger
ignoring --pip.

> What *is* a problem is if --pip is in setup.cfg, and one invokes `pip
> install --egg .`.  I wasn't quite able to make that go into an
> infinite loop, but it did invoke pip.main recursively, and stuff broke
> on the second invocation for reasons not clear to me.

Yeah, but honestly I don't think pip install --egg is that important a
use case. I may be wrong (there's lots of ways people use pip that I
know nothing of :-)) but as a starting point it might be OK just to
say that at the same time as the --pip flag was introduced, "pip
install --egg" was deprecated (and we explicitly document that pip
install --egg is known to interact badly with setup.py --pip).

Anyway, thanks for the explanation, I see what you're intending now.

Paul