This build shows as successfully completing, despite 6 errors in the Python test suite: https://ci.appveyor.com/project/Cantera/cantera/build/1.0.51

Appveyor is being a real pain, dealing with false positives (the pip problem) and false negatives (this problem...)

By the way, in looking at that log, there seems to be another error related to pip that didn't cause the build to fail, which is that the upgrade process for pip for pip fails because a directory is not writable. Also, apparently the --egg option is deprecated.