--egg ignored when wheels available

[jaraco]

• Pip version: 8.1.2
• Python version: 3.5.1
• Operating System: OS X 10.11.5

Description:

I'm working to use pip in place of easy_install, but due to #3, I have to install packages as eggs. So I tried installing a package as an egg, but because a wheel was available, pip installed that, and not as an egg. I would expect (in order of preference):

1. Pip would convert the wheel to an egg and install it.
2. Pip would disregard wheels and build and egg from a source distribution and install it.
3. Pip would raise an error that it can't install as an egg when a wheel is available.

What I've run:

$ python -m pip install --egg setuptools
Collecting setuptools
  Using cached setuptools-21.1.0-py2.py3-none-any.whl
Installing collected packages: setuptools
Successfully installed setuptools-21.1.0
$ python -c "import setuptools; print(setuptools.__file__)"
/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/site-packages/setuptools/__init__.py

[dstufft]

I feel like this is yet another reason that --egg should go :/

[RonnyPfannschmidt]

@jaraco since the actual issue causing #3 is, that editable installs and "normal" non egg installs are incompatible, i see this more of a bug of the setuptools develop command than pip

[jaraco]

I feel like this is yet another reason that --egg should go :/

Yes, I share that sentiment. And if there were a viable alternative, I would agree. I'm conscientiously seeking to find that alternative.