Summary

Propagating panic for cycle head that panicked in an earlier execution in that revision

ty seems to give up inside of a monolithic function that spans... a lot of lines, and a lot of the definitions are Never from a certain point and hovering/clicking over them spams that error.

Unsure if the Never business is related to the panic business, I was previously already advised that the codebase is way too complex as is.

Hovering over some variables sometimes spams the error above, or it just happens when scrolling the codebase.

I can't seem to reproduce this with cli ty, which takes its time but works, just in the combination with the VSC extension.

It's Tauon's codebase that's triggering this - https://github.com/Taiko2k/Tauon - specifically src/tauon/t_modules/t_main.py

Version

ty 0.0.9 (f1652f0 2026-01-05)

Repro: Open src/tauon/t_modules/t_main.py in VSC, and start VSC anew. It seems that the panic is not a 100% guarantee, but it happens very often.

2026-01-07 17:17:15.715070957  INFO Version: 0.0.9 (f1652f05d 2026-01-05)
2026-01-07 17:17:15.809072027  INFO Defaulting to python-platform `linux`
2026-01-07 17:17:15.819507076  INFO Python version: Python 3.10, platform: linux
2026-01-07 17:17:15.869556006  INFO Indexed 35 file(s) in 0.004s
2026-01-07 17:17:25.560761314  WARN Propagating panic for cycle head that panicked in an earlier execution in that revision
2026-01-07 17:17:25.685805348  WARN Propagating panic for cycle head that panicked in an earlier execution in that revision
...