pip v10 breaks Debian/Ubuntu pip3 command

[iamarcel]

Maintainer note: Anyone that still gets this issue please see #5599.

---

• Pip version: 10.0.0
• Python version: 3.5.2
• Operating system: Ubuntu 16.04 (EDIT: tested on debian:9.4 too, same thing happens)

Description:

When upgrading pip (to v10) on at least Ubuntu 16.04, the pip3 command stops working ("cannot import main", see below). This is on a fresh install.

What I've run:

(Note that I've stripped out all the apt output etc., since I think it's not needed here. Let me know if you still want it!)

me@host$ sudo docker run -it ubuntu:xenial

root@container# apt update && apt install python3-pip

root@container# pip3 --version
pip 8.1.1 from /usr/lib/python3/dist-packages (python 3.5)

root@container# pip3 install --upgrade pip
Collecting pip
  Downloading pip-10.0.0-py2.py3-none-any.whl (1.3MB)
    100% |################################| 1.3MB 1.4MB/s 
Installing collected packages: pip
  Found existing installation: pip 8.1.1
    Not uninstalling pip at /usr/lib/python3/dist-packages, outside environment /usr
Successfully installed pip-10.0.0

root@container# pip --version
pip 10.0.0 from /usr/local/lib/python3.5/dist-packages/pip (python 3.5)

root@container# pip3 --version
Traceback (most recent call last):
  File "/usr/bin/pip3", line 9, in <module>
    from pip import main
ImportError: cannot import name 'main'

root@container# cat /usr/bin/pip3
#!/usr/bin/python3
# GENERATED BY DEBIAN

import sys

# Run the main entry point, similarly to how setuptools does it, but because
# we didn't install the actual entry point from setup.py, don't use the
# pkg_resources API.
from pip import main
if __name__ == '__main__':
    sys.exit(main())

Not sure if this is something that should be fixed on the pip side or on the Debian side.

[RonnyPfannschmidt]

thats a debian issue

[RonnyPfannschmidt]

on extra note - replacing the system pip using pip is always an act of system-vandalism where the one inflicting it is responsible for the fallout

[pfmoore]

I'd suggest you should wait for a proper apt packaged copy of pip 10 from Debian - as @RonnyPfannschmidt says, you shouldn't be using pip to upgrade your system packages...

Looks like the Debian pip3 script uses pip's internals, so getting a pip10 compatible fix is definitely up to them (and I'd fully expect them to wait on releasing their pip10 package until they have that sorted).

[fake-name]

on extra note - replacing the system pip using pip is always an act of system-vandalism where the one inflicting it is responsible for the fallout

Convince the debian/ubuntu people to not vendor and then let rot half their packages, and that'd be a valid argument.

[pradyunsg]

You can use virtualenv or venv to isolate yourself from the system pip installation.

You should not be modifying the package-manager managed files (here the system pip installation) -- I think they don't expect users to modify things -- it is likely not supported by Debian. It's bound to cause issues like this.

[slabua]

Same issue on Fedora, too.

[di]

Perhaps there should be a "beta" channel, or some similar mechanism for people to do more testing prior to release, rather then just dumping a broken version on pypi and causing everyone's builds to explode.

@fake-name There were two pre-releases made:

• 10.0.0b1 was released on Mar 31st
• 10.0.0b2 was released on April 2nd

[RonnyPfannschmidt]

@fake-name additionally the general suggestion for usage on all distros is - use a virtualenv, don't vandalize the system, and that works - people just font follow it and then wonder when stuff breaks and blame pip

there has been plenty of manual and automated testing with virtualenvs which works

also in a virtualenv at least there should be no debian made pip3 command - so what the heck are you talking about wrt this breaking in virtualenvs - please provide enough data to actually verify instead of whining about breakages without providing the data needed to verify them

pip is volunteer driven, not a company with dozens of employees

[fake-name]

Deleted. was confusing this with #5220

I'm a derp.

[iamarcel]

Thanks, hadn't realized that replacing the system pip was a bad idea but it makes sense. However, it would be good UX if pip would not nag about upgrading in that case. Would that be possible? I reckon a lot of people (including me) would just do whatever "the thing" asks them to do.

[RonnyPfannschmidt]

@fake-name thanks for following up - its surprisingly common to mismatch the detail issue when a major release has multi-faceted impact and part of it tries to ruin you day

[pfmoore]

it would be good UX if pip would not nag about upgrading in that case

Distribution vendors could certainly patch pip to remove that warning (or better, replace it with a similar check against the system packages) along with the other patches they make. I'm not sure how base pip could detect that it's running from a system packaged installation without co-operation from the distribution, but if there's a way to do so that's something we could consider (but be aware that in my experience we get as much negative feedback from getting such heuristics wrong as we do from not including heuristics at all...)