`python setup.py install` command should error out and ask user to use `pip`

[jdemeyer]

The only way to have a working installation of widgetsnbextension is to use pip.

The usual python setup.py install does not work, since that invokes setuptools (although setup.py seems to be written at some point with a conditional import of setuptools) and the setup() function of setuptools does not handle data_files correctly.

Note that it's not a problem for me to use pip but it's at least unexpected that python setup.py install does not work. So either this should be fixed or detected such that an error can be raised.

CC @embray @SylvainCorlay

[jdemeyer]

Even just adding a warning "this package cannot be installed using python setup.py install" in the install docs would already help.

[embray]

I don't think that's a quite accurate description of the problem, because as I've explained several times pip always uses setuptools.

[jdemeyer]

Right, the problem is not the setuptools module, the problem is the default behaviour of the setup() function of setuptools.

[embray]

Anyways I don't think this is a problem for ipywidgets.

[Carreau]

python setup.py install

This should not be used and has not been really supported for a long time. It will be used internally by pip. If you see anywhere in our docs a direct mention to python setup.py install please point the to us so that we can remove it. The problem with a warning of "don't use XXX" is that user will remember XXX, and do XXX – from experience from other IPython options. Especially if the line can be copy/pasted in a terminal.

We'll likely try to add a stricter check in many setup.py to be sure they are ran by pip.

[jdemeyer]

We'll likely try to add a stricter check in many setup.py to be sure they are ran by pip.

If possible, that would be a great idea.

[malatiyyah]

I have the same problem

[jdemeyer]

I guess the problem is that eggs are not supported. I solved that in cysignals with a fake bdist_egg command: https://github.com/sagemath/cysignals/blob/master/setup.py#L185