pip3 installs under python3.5

I've confirmed that the shebang for /usr/bin/pip3 is /usr/bin/python3.5 where it should be /usr/bin/python3 and that affects where pip3 will install things by default. I should mention that in the face of multiple supported versions of Python 3, "pip3" is ambiguous anyway, and you might want to use `python3.4 -m pip install` to be explicit. Still, pip3 by default should install in the default Python 3.

(Aside: note that upstream pip is trying to break the link between the shebang and where things get installed. That won't help for Wily though. Also, this isn't Xubuntu specific).

Well, that's very interesting. I just built the source package on Wily and pip3's shebang is /usr/bin/python3. I'll do a bit more testing but maybe it just needs a no-change rebuild in Wily?

I have a fix. Prepping SRU.

The fix is to force `dh_python3 --shebang /usr/bin/python3` in d/rules.

This bug was fixed in the package python-pip - 1.5.6-7ubuntu2

---------------
python-pip (1.5.6-7ubuntu2) xenial; urgency=medium

  * d/rules: Force the shebang for /usr/bin/pip3 to be /usr/bin/python3.
    (LP: #1518023)

 -- Barry Warsaw <email address hidden> Thu, 19 Nov 2015 14:49:14 -0500

Hello Régis, or anyone else affected,

Accepted python-pip into wily-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/python-pip/1.5.6-7ubuntu1.1 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

Just tested version 1.5.6-7ubuntu1.1 on wily-proposed and it works.

I tested this also and it works for me. When will this get released to updates?

The verification of the Stable Release Update for python-pip has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

This bug was fixed in the package python-pip - 1.5.6-7ubuntu1.1

---------------
python-pip (1.5.6-7ubuntu1.1) wily; urgency=medium

  * d/rules: Force the shebang for /usr/bin/pip3 to be /usr/bin/python3.
    (LP: #1518023)

 -- Barry Warsaw <email address hidden> Thu, 19 Nov 2015 14:49:14 -0500

For users that want to use Python 3.5, now that this has been changed, what is the supported way to install pip for Python 3.5?

You can probably use the update-alternatives system to set the system
python version to default to python 3.5. Otherwise it might be easier to
use user level tools such as virtualenv and pyenv to have multiple python
versions installed.

On Thu, Jan 7, 2016 at 10:05 AM John Hagen <email address hidden> wrote:

> For users that want to use Python 3.5, now that this has been changed,
> what is the supported way to install pip for Python 3.5?
>
> --
> You received this bug notification because you are subscribed to a
> duplicate bug report (1519474).
> https://bugs.launchpad.net/bugs/1518023
>
> Title:
> pip3 installs under python3.5
>
> Status in python-pip package in Ubuntu:
> Fix Released
> Status in python-pip source package in Wily:
> Fix Released
> Status in python-pip source package in Xenial:
> Fix Released
>
> Bug description:
> On a freshly installed and updated xubuntu 15.10, /usr/bin/python3
> links to /usr/bin/python3.4
>
> However, pip3 (from repository) installs packages under python3.5
>
> Fix: Either change the symlink (it may break some pre-python 3.5 code
> in the distro though) or the first line of pip.
>
> ProblemType: Bug
> DistroRelease: Ubuntu 15.10
> Package: python3 3.4.3-4ubuntu1
> ProcVersionSignature: Ubuntu 4.2.0-16.19-generic 4.2.3
> Uname: Linux 4.2.0-16-generic x86_64
> ApportVersion: 2.19.1-0ubuntu5
> Architecture: amd64
> CurrentDesktop: XFCE
> Date: Thu Nov 19 15:36:29 2015
> InstallationDate: Installed on 2015-11-19 (0 days ago)
> InstallationMedia: Xubuntu 15.10 "Wily Werewolf" - Release amd64
> (20151021)
> SourcePackage: python3-defaults
> UpgradeStatus: No upgrade log present (probably fresh install)
>
> To manage notifications about this bug go to:
>
> https://bugs.launchpad.net/ubuntu/+source/python-pip/+bug/1518023/+subscriptions
>

Changing /usr/bin/python3 to point to /usr/bin/python3.5 on a 15.10 system is guaranteed to break things. Don't do that.