Useful when an app appears hung or deadlocked.
Section: Async, Web, and Production Troubleshooting
Dump stack traces for all threads
python
python
import faulthandler
import signal
faulthandler.register(signal.SIGUSR1)Explanation
After registering a signal, send `SIGUSR1` to the process to dump thread stack traces.
Learn the surrounding workflow
Compare similar commands or jump into common fixes when this command is part of a bigger troubleshooting path.
Related commands
Same sheet · prioritizing Async, Web, and Production Troubleshooting
Enable debug mode programmatically
Turn on event loop debugging in code.
Start a simple HTTP server for quick testing
Serve files locally to reproduce client behavior.
Print the current exception traceback
Dump the active exception traceback in an except block.