Line coverage in Python does not seem to work on multithreaded programs #103
Description
This is about https://github.com/TNO-S3/WuppieFuzz-Python
Describe the bug
While testing a customer app, the line coverage was 12%, always, also at the start.
Versions:
Latest
To Reproduce
Fuzz a Python target with line coverage enabled. Open the resulting database in Grafana. See line coverage is constant.
Expected behavior
Line coverage starts at 0 and increases.
Screenshots
Classified, unfortunately.
Additional context
This application was multithreaded, and we suspect line coverage was monitoring the "wrong" thread. So the first nontrivial task is to find a Python target to reproduce this bug.