build of python3 snap fails with 'error: option --single-version-externally-managed not recognized'

[Seth Johnson]

I'm attempting to repackage a desktop app (unity-tweak-tool in this case) as a snap, however 'snapcraft build' always fails with this error:

    error: option --single-version-externally-managed not recognized

As far as I can tell this has something to do with the way pip install is being called by snapcraft, but I'm not completely sure.

[Sergio Schvezov (sergiusens)]

Does it work with the latest snapcraft and does it work doing `pip install` from the sources?

[Launchpad Janitor (janitor)]

[Expired for Snapcraft because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for snapcraft (Ubuntu) because there has been no activity for 60 days.]

[Jason C. McDonald (codemouse92)]

Slamming into this myself. Here's the relevant information:

snap 2.26.14
snapd 2.26.14
series 16
ubuntu 17.04
kernel 4.10.0-28-generic
python 3.5.2

Full text of both `setup.py` and `snapcraft.yaml` attached.

Full error is as follows:

------------------------------------------------------------

Installing collected packages: appdirs, idna, Kivy, certifi, Omission, docutils, Kivy-Garden, Pygments, urllib3, chardet, requests
Successfully installed Kivy-1.10.0 Kivy-Garden-0.1.4 Omission-1.0 Pygments-2.2.0 appdirs-1.4.3 certifi-2017.7.27.1 chardet-3.0.4 docutils-0.13.1 idna-2.5 requests-2.18.3 urllib3-1.22
/home/jason/Code/Repositories/omission/parts/omission/install/usr/bin/python3 setup.py --no-user-cfg install --single-version-externally-managed --user --record install.txt
/home/jason/Code/Repositories/omission/parts/omission/install/usr/lib/python3.5/distutils/dist.py:261: UserWarning: Unknown distribution option: 'install_requires'
  warnings.warn(msg)
usage: setup.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
   or: setup.py --help [cmd1 cmd2 ...]
   or: setup.py --help-commands
   or: setup.py cmd --help

error: option --single-version-externally-managed not recognized
[Errno 1] Operation not permitted: '/home/jason/Code/Repositories/omission/parts/omission/install/usr/lib/x86_64-linux-gnu/libBrokenLocale.so'

[Jason C. McDonald (codemouse92)]

That code blindness for you. Note in my 'setup.py', I had 'from distutils.core import setup', but I SHOULD have had 'from setuptools import setup'.

[Sergio Schvezov (sergiusens)]

Yes, we currently only support pip installable projects, which means `--single-version-externally-managed` is not supported, which means you should use `setuptools` instead of `distutils.core`.

That said, we would welcome a `distutils` plugin in snapcraft.