locations.locations.distutils_scheme() reports incorrect header paths for editable installs

[nils-werner]

• Pip version: 8.1.2
• Python version: 2.7.11
• Operating System: OSX 10.11

Description:

You can get the location of header files of an installed package -- e.g. pybind11 -- using

>>> pip.locations.distutils_scheme('pybind11')['headers']
'/virtualenv/include/site/python2.7/pybind11'

However the returned path is only correct if it was installed regularily. When doing an editable install the headers are not copied to that directory and the path is incorrect for editable installs.

What I've run:

$ pip install pybind11
$ python -c "from pip import locations as l; print l.distutils_scheme('pybind11')['headers']"
/virtualenv/include/site/python2.7/pybind11

$ pip uninstall pybind11
$ pip install -e ./pybind11
$ python -c "from pip import locations as l; print l.distutils_scheme('pybind11')['headers']"
/virtualenv/include/site/python2.7/pybind11

The path for both is the same, but for an editable installs no headers are ever copied.

[xavfernandez]

It looks like you are using pip internals to retrieve informations, which is strongly discouraged as they are likely to change without notice in the future and completely unsupported.

[pradyunsg]

Hi @nils-werner!

pip does not support the use of it's internal APIs. The upcoming pip 10 will be breaking the exact snippet you've posted.

More on that here: https://mail.python.org/pipermail/distutils-sig/2017-October/031683.html

[phdowling]

@pradyunsg Does that mean pybind11 will actually stop working at that point? Because that seems to be using exactly this line: https://github.com/pybind/pybind11/blob/master/pybind11/__init__.py#L9

[pradyunsg]

Yep. You'll want to open an issue there. I don't have a link handy to the announcement to distutils-sig.

…

On Wed, 8 Nov 2017, 08:33 Philipp Dowling, ***@***.***> wrote: @pradyunsg <https://github.com/pradyunsg> Does that mean pybind11 will actually stop working at that point? Because that seems to be using exactly this line: https://github.com/pybind/pybind11/blob/master/pybind11/__init__.py#L9 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#3696 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ADH7SbfIDO1BLau-0Q0iqL9iJsEch_0Yks5s0RoKgaJpZM4IiV29> .

[pfmoore]

Link to the relevant section of the docs: https://pip.pypa.io/en/latest/user_guide/#using-pip-from-your-program
Link to the distutils announcement: https://mail.python.org/pipermail/distutils-sig/2017-October/031642.html