[UI bug] Track Event Callstacks tab empties when time range selection includes start or end

[anakryiko]

When selecting some tracks containing TrackEvents with callstacks, Track Event Callstacks tab will show flamegraph only if time selection doesn't include the very start and/or the very end of time line. I captured the behavior in a video to demonstrate.

Screen.Recording.2026-01-23.at.9.44.31.AM.mov

[LalitMaganti]

I noticed this as well a couple of days ago and forgot to file something. This is a general bug with any type of selection not just for callstacks. There seems to be some issue with any selection including the very left/right of the page.

[stevegolton]

I can't seem to repro this at all. @anakryiko do you have a trace you can share?

[LalitMaganti]

Repros for me on the test track event callstack trace in our repo: https://ui.perfetto.dev/#!/?s=67f4aeecea266d4e81cc4e34cad5fe7b69e98197

Also attached:

track_event_test.pb.gz

[anakryiko]

@stevegolton so it seems if you do cmd+A selection, everything works. But if you drag time bar with the mouse, then stacks "disappear". Maybe that will give you some more clues.