Installation fails on Ubuntu 16.04

[ms-lilibeth]

Installation fails with the following error:

Running setup.py install for retext ... error
    Complete output from command /usr/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-install-eqsx1qml/retext/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-record-713lwp8h/install-record.txt --single-version-externally-managed --compile:
    usage: -c [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...]
       or: -c --help [cmd1 cmd2 ...]
       or: -c --help-commands
       or: -c cmd --help
    
    error: option --single-version-externally-managed not recognized
    
    ----------------------------------------
Command "/usr/bin/python3 -u -c "import setuptools, tokenize;__file__='/tmp/pip-install-eqsx1qml/retext/setup.py';f=getattr(tokenize, 'open', open)(__file__);code=f.read().replace('\r\n', '\n');f.close();exec(compile(code, __file__, 'exec'))" install --record /tmp/pip-record-713lwp8h/install-record.txt --single-version-externally-managed --compile" failed with error code 1 in /tmp/pip-install-eqsx1qml/retext/

[mitya57]

This is fixed in the latest Git, and the fix will be in the next release. Please see #295 and #324 for the previous discussions.