[BUG] --install-options are suppressed by pip 20.2.3

[alikhtag]

May not be a bug but I would like to just to inform that documentation may not be up to date. And maybe you may want to do some changes (in code or docs) so that latest version of pip 20.2.3 can aligned.

Describe the bug
When using latest version of pip 20.2.3. --install-options containing paths are no longer supported.
See also pypa/pip#7309

To Reproduce
When running as decribed in DOCS one will see an error:

pip install --upgrade pip==20.2.3 
pip install graphite-web==1.1.7 --install-option="--prefix=/srv/graphite" --install-option="--install-lib=/srv/graphite/webapp"

ERROR: Location-changing options found in --install-option: ['--install-lib', '--prefix'] from command line. This is unsupported, use pip-level options like --user, --prefix, --root, and --target instead.

Environment (please complete the following information):

• OS flavor: Ubuntu 18.04 using Docker
• Graphite-web version: 1.1.7
• Django/Python version: 3.7
• Setup type: pip 20.2.3

[earthgecko]

@alikhtag there is a workaround described in #2566

For now a simple workaround is to use virtualenv 16.7.10 if you can.

If you know what you are doing and you have virtualenv 20.0x installed with the system pip, then you can install 16.7.10

pip uninstall virtualenv
pip install virtualenv==16.7.10

# or
pip3 uninstall virtualenv
pip3 install virtualenv==16.7.10

Install the graphite virtualenv with 16.7.10 and install graphite and your installation will now work as per the docs.

You can then update virtualenv again, however please assess how appropriate this method is for you first.

[deniszh]

virtualenv downgrade will work, but we need to adopt new way, I think.

[alikhtag]

I was using docker image, where I can just do pip install pip==20.1, I think this may work around will work for most python virtual environments as well even when downgrading.