Pylint cannot be run from within Jenkins
The problem was in the Jenkins shell and the lack of virtualenv, apparently - even though Jenkins was configured to use bin/bash.
The way I solved it was:
steps { sh 'bash ./lintpython.sh' }
Inside lintpython.sh:
#!/bin/bashpython3 -m venv ~/.somevenvsource ~/.somevenv/bin/activatepip install --upgrade pip &&\ pip install -r requirements.txtpylint app.py