[Distutils] Removing dependency_links

[Donald Stufft]

On Oct 26, 2013, at 10:14 PM, Donald Stufft <donald at stufft.io> wrote:

> I would like to remove dependency_links from pip, and ideally
> also setuptools.
> 
> In implementing the ensurepip module from PEP453 I realized that
> even with the ``--no-index`` flag pip was still attempting to
> reach the internet. After a little bit of investigation I realized
> that the reason for this was setuptools use of dependency links.
> From my investigation it appears that setuptools uses these in order
> to enable secure automatic installation of the ssl dependencies on
> Python < 2.6.
> 
> Overall this feature is a security concern, a malicous package could
> "pin" any package they want by depending on it and adding a dependency
> link a version 100000. This would be more or less transparent to
> the end user.
> 
> I was looking to see what sort of impact this would have. There are
> currently 167,796 source files hosted on PyPI and of those files
> 4,005 of them have any dependency links at all. Looking at it a
> different way, there are 36,070 total projects on PyPI and 411 of them
> use this feature. So this is ~2% of the files or ~1% of the projects.
> 
> So it appears that this isn't a particularly popular feature, I believe
> that it is a *bad* idea that inverts the expected control and should
> be removed from both pip and setuptools. In setuptools case it does use
> it in the only reasonable way I can imagine, however I think setuptools
> should just stop trying to automatically install those dependencies
> for Pythons < 2.6 and similarly to pip just print an error and expect users
> to get and install them on their own. As a reminder there are very
> few downloads from PyPI that are from Pythons < 2.6 [1]
> 
> [1] https://caremad.io/blog/a-look-at-pypi-downloads/
> [2] https://gist.github.com/dstufft/7173539
> 
> -----------------
> Donald Stufft
> PGP: 0x6E3CBCE93372DCFA // 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA
> 
> _______________________________________________
> Distutils-SIG maillist  -  Distutils-SIG at python.org
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A list of projects that use dependency links: https://gist.github.com/dstufft/7177500

-----------------
Donald Stufft
PGP: 0x6E3CBCE93372DCFA // 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA

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