pip install --editable does not support --target

[mitsuhiko]

For a plugin system I'm attempting to pip install --editable into a local path of my choice. For regular plugins I am installing with pip install --target and that works just fine, but for local development I want to do the same with egg links.

The target directly gets added to the pkg resources working set as well as as a site directory by myself, so I do not care about any of that stuff. All I need is --target to not fail. Right now it gives a bad internal error that --home is not supported as this is only allowed to install but not to develop which it invokes.

As a super shitty work around I do something like this right now:

$ PYTHONPATH='/target/path/' pip install --editable my/plugin/ --install-option='--install-dir=/target/path/' --no-deps

And then later on install the plugins' dependencies manually.

[mitsuhiko]

In case you are curious why the hell I need this have a look at this: https://github.com/mitsuhiko/lektor/blob/16dab7df64bb18f8d7ebe5fcbf935f22629d8ba8/lektor/packages.py

It basically uses pip as a local helper system to install plugins for an application.

[piotr-dobrogost]

Already raised in issue #562

[dstufft]

Closing this as a duplicate of #562.