Python: ImportError: No module named _pluggy

Question

I am getting ImportError: No module named _pluggy error when running tests using pytest.

Then I tried installing pluggy using pip install pluggy. It installs pluggy==0.6.0 successfully, but is still giving the error.

Versions List (From running pip freeze | grep pytest)

• pytest==3.3.1
• pytest-cov==2.5.1
• pytest-metadata==1.5.0
• pytest-runner==3.0
• pluggy==0.6.0
• Python 2.7.12

Shown below is the stack trace

Tests run successfully when run in a virtualenv. What are the possible causes which can cause this error in a non-virtualenv environment?

Answer 1

As it was pointed out by @bouteillebleu the issue was in pytest-metadata package.

The solution was to upgrade the package

pip install --upgrade pytest-metadata