# Linux Kernel Module Cheat

##### 24.22.9.1. M5_OVERRIDE_PY_SOURCE

https://stackoverflow.com/questions/52312070/how-to-modify-a-file-under-src-python-and-run-it-without-rebuilding-in-gem5

Running gem5 with the `M5_OVERRIDE_PY_SOURCE=true` environment variable allows you to modify a file under src/python and run it without rebuilding in gem5?

We set this environment variable by default in our run script.

How `M5_OVERRID_PY_SOURCE` works is shown at: gem5 `m5.objects` module.