Debug mode for python tests don't stop at a breakpoint

[aritrachatterjee15]

IDEA Ultimate version: 2018.2.5
OS: Ubuntu 16.04

I'm getting started with Pants for a python project. I'm stuck when trying to debug test cases.

Importing the project to intellij works fine. But, right clicking on a test directory and selecting 'Debug -> Pants tests in XYZ' doesn't seem to stop the execution at a breakpoint as expected during a typical debug cycle.

Also, configuring an environment variable in the Run/Debug configurations does not seem to have an effect on the running test case.

Is debugging for python unsupported? If yes, are there recommendations on what's the best way to achieve this?