[TIP] ImportError (No module named 'pytest') - weird coverage and py interaction as a result of tox dependency

Chris Withers chris at simplistix.co.uk
Thu Jul 3 01:30:43 PDT 2014

Hi All,

So, with:

nosetests --with-xunit --with-cov

...I get the following failures on Python 3.* in Linux and Mac:

ERROR: Failure: ImportError (No module named 'pytest')

Full and nasty traceback here:


The weird thing is that if I drop the --with-cov, things work fine.

Has anyone seen anything similar?

None of the packages involved seem to have changed recently, so I'm a 
little at a loss as to what has changed.


Simplistix - Content Management, Batch Processing & Python Consulting
            - http://www.simplistix.co.uk

More information about the testing-in-python mailing list