--target does not work with --user

[dholth]

On Ubuntu 16.04, pip 8.1.1, --user is default, and --target does not work. Is there any reason to not just have an explicit command line argument --target override implicit --user? Needed for a setup-requires shim.

  File "/usr/lib/python2.7/distutils/command/install.py", line 289, in finalize_options
    raise DistutilsOptionError("can't combine user with prefix, "
DistutilsOptionError: can't combine user with prefix, exec_prefix/home, or install_(plat)base

[RonnyPfannschmidt]

well, its more of an ubuntu bug, they blindly patch things and then the world breaks ^^

[ntninja]

Got bitten by this today (Debian 9), officially Debian mentions #1668 as reason of applying this patch. The official work-around is to use the --system parameter to disable --user, but that will break whenever Debian's pip3 is not used. 😡

[dstufft]

Yea, I told Debian/Ubuntu not to apply said patch until we got all the issues worked out with it, they didn't want to wait on that. You'll need to raise the issue with them since their patch is causing the issue.

[dstufft]

The underlying issue here is that it's non-sensical for --target and --user to be used on the same command line, but the current setup doesn't make it easy to determine where a particular value came from. We're currently relying on our default of --user to not being on, and by switching the default Debuntu has broken an assumption we've made throughout the code base.

But please, file an issue with bugs.debian.org so that downstream can track issues with their patch and can get this resolved for you.

[dholth]

reported

[asmodehn]

I have a related issue for the same reason :

$ cat /etc/issue
Ubuntu 16.04.1 LTS \n \l
$ uname -a
Linux kinetic-VirtualBox 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux

$ pip install -r requirements.txt --prefix test_loc/
ERROR: Can not combine '--user' and '--prefix' as they imply different installation locations
You are using pip version 8.1.1, however version 8.1.2 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.

Note this might be relevant to #1668 as well, since, even if --user is default, I may want to redirect where python packages get installed...
I believe the same is true for --target.

Or should I create a separate issue for this ?

[techtonik]

So does Ubuntu 16.10 fix that?

[tfoote]

@dholth could you link to the issue on debian?

[techtonik]

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=830892

[techtonik]

To me all three --user, --system and --target are mutually exclusive. Any explicit option should change the default and not depend on that.

[techtonik]

This patch should clarify the message for users af03a65