Why can't I call pip with --target and --editable?

Question

I\'m using

cd MyPackage

pip install --target deploy_directory .

to prepare packages for deployment on Google App Engine, but

Answer 1

This is known to be broken since a long time. See https://github.com/pypa/pip/issues/3246 and https://github.com/pypa/pip/issues/562.

In the second link it is mentioned that some developers covered their use case with replacing --target by --src. I have not tried this myself though.