Installing packages with relative paths fails -- discussion

[techalchemy]

See #936 -- basically boils down to is_file checks for local files. This issue is to open a broader discussion for the proper way to handle checks for local files during installation. Previously we have had several issues (#817, #540 for instance) where users needed to install a local sdist in the project directory (in that case a file, properly speaking, as a tar.gz or a .zip), and a relative path to a local directory containing a valid setup.py (e.g. pipenv install -e ../somedirectory/ or the equivalent of pip install -e ../...).

As a consequence we currently are mainly checking only that a path exists locally before attempting to install it as a local path, no matter whether the user supplied a preceding ./ if it is in the current / project directory (we could require this), or whether the path is a file which can be installed with pip, or, if it is a directory, if that directory contains a python package at all and if so, if it can be installed with pip.

Essentially I would propose that we start the discussion with this set of options and whether they are suitable/viable:

• Our initial position for filesystem locations was to require file:// URIs, but we budged on this because pip allows local paths and because users often use this syntax. We could enforce a local path 'uri' by enforcing ./ and ../ syntax and asking if the user meant ./path if we find a matching one before proceeding
• We could ignore any directories in the project root that are not explicitly installed in editable mode - what are the potential consequences of this?
• We could attempt to pass through existing directories to a pip install as we are doing now, but instead of failing and pretending to succeed, we could figure out a way to fail silently and proceed to pypi or whatever repository the user has chosen. This seems like the most idiomatic approach potentially, although I'm not sure how complex the implementation is.
• We could be dumb and just check for the presence of setup.py in any directory that matches a requested path and, if it is missing, dont bother trying to install that directory and just query the repository

I personally am only opposed to the first option, I don't really have strong feelings on the others and could see one or any combination of those working well. There could easily be other options I'm not considering. I'd be curious to hear what others have to say

/cc @krismolendyke @kennethreitz @erinxocon @nateprewitt (when you guys have time)

[techalchemy]

/cc @vphilippon

[techalchemy]

See #914 also

[kstohr]

Apologies, I just submitted a query on this issue... and didn't make the connection.

The user should determine when/whether local packages should be added to the pipfile explicitly rather than automatically detecting and installing which could cause issues/complications for projects in development. The above mentioned pipenv install -e ./path/to/setup.py seems intuitive to me...

[techalchemy]

Closing this -- resolved via #958