The problem

1. Subtly break your installation while working on an extension
2. Run python3 -moctoprint serve --debug
3. Hit a fatal error on startup
4. Observe no stack trace, despite --debug

IMHO, requiring people to hack source code just to get useful error information is not acceptable behavior.

Did the issue persist even in safe mode?

Yes, it did persist

If you could not test in safe mode, please state why ("currently printing" is NOT an excuse!)

No response

Version of OctoPrint

current master

Operating system running OctoPrint

not relevant

Printer model & used firmware incl. version

No response

Browser and version of browser, operating system running browser

No response

Checklist of files to include below

• Systeminfo Bundle (always include!)
• Contents of the JavaScript browser console (always include in cases of issues with the user interface)
• Screenshots and/or videos showing the problem (always include in case of issues with the user interface)
• GCODE file with which to reproduce (always include in case of issues with GCODE analysis or printing behaviour)

Additional information & file uploads

$ python3 -moctoprint serve --debug --port 50081
[ lines about timing elided ]
2024-03-21 08:25:33,078 - octoprint.startup - CRITICAL - Could not initialize logging: Unable to configure formatter 'colored'
2024-03-21 08:25:33,079 - octoprint.startup - CRITICAL - There was a fatal error starting up OctoPrint.
Could not initialize logging: Unable to configure formatter 'colored'
There was a fatal error starting up OctoPrint.