download attempts to build instead of just downloading

[benhosmer]

• Pip version: 9.0.1
• Python version: 2.7
• Operating System: CentOS 7.3.1611

Description:

I'm attempting to use the download option to download a tar.gz from pypi of the GDAL package

What I've run:

.venv/bin/pip download GDAL==2.1.0 --verbose --no-cache-dir --no-dependencies -d ./

  Saved ./GDAL-2.1.0.tar.gz
  Running setup.py (path:/tmp/pip-build-Gk23rl/GDAL/setup.py) egg_info for package GDAL
    Running command python setup.py egg_info
    running egg_info
    creating pip-egg-info/GDAL.egg-info
    writing pip-egg-info/GDAL.egg-info/PKG-INFO

InstallationError: Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-T9q_eG/GDAL/

Pip appears to be running setup.py which isn't what I want. I need to build the GDAL package with some optional flags that point to other header files.

[RonnyPfannschmidt]

That's a needed feature, setup.py is usually dynamic, egg info extracts metadata pip needs

[benhosmer]

That's a needed feature, setup.py is usually dynamic, egg info extracts metadata pip needs

Do you mean a needed feature in that the capability should be added, or that it works as intended and I'm just using it wrong?

[pfmoore]

It's how pip works, because we have to execute setup.py to get the metadata. You're not using it wrongly.

One key reason it needs the metadata is to get dependency information. It's possible that it would be OK to skip getting the metadata if --no-dependencies is set, but pip doesn't do that at the moment.

[xavfernandez]

pip download pkgA will download the pkgA and by default all of its dependencies.

If pkgA is provided as a sdist (i.e. .tag.gz or .zip file), it means that pip will have to execute setup.py to extract the dependencies.

If you don't need the dependencies, pip download pkgA --no-deps (or --no-dependencies) will only download pkgA and won't execute any code.

[pfmoore]

@xavfernandez But doesn't the issue description show --no-dependencies still executing setup.py? I'm inclined to think this is an error on pip's part (unless the metadata is needed for some other aspect of pip download's behaviour).

[xavfernandez]

Hmm you're right, I read too quickly :-/

[dstufft]

Duplicate of #1884.