tox but with conda

conda, tox, testing, virtualenv
pip install ctox==0.1.3



tox but with conda.

Build Status

This is a really rough hack to replicate tox using conda (Note that tox is professionally supported whilst ctox isn't supported). In the long-term a much better solution is to add conda support to tox...


  • conda envs and dependancies are cached (very naively)
  • some tox substitutions (some missing features)
  • no some cli options (lots of missing features)
  • no parallel support (yet)
  • bugs (probably lots)

However, the neat thing is that it makes tox-like testing on a machine with conda installed, but not all python versions are installed.

In conclusion, you're probably better off using tox, here be 🐉s.


Have conda installed on your system. The recommended way (I think) is via miniconda, the not recommended way (which will almost certainly fail) is via pip, please don't use this with conda installed via pip.

In the project's directory (which has a tox.ini file):

cd project_dir
# or to pdb into any failing environments
ctox -- --pdb --pdb-fail

Note this assumes you have something like nosetest {posargs} (or py.test {posargs}) in the projects tox.ini file. which this will be replaced with nosetest --pdb --pdb-fail (or py.test --pdb --pdb-fail).


I was sick of InterpreterNotFound when trying to use tox having installed python with conda. This solves that and I thought it wouldn't take very long to put together. No doubt I should've just hacked on tox, which in the long-run will be the best solution, but there you are!