With Fission and SHIP, I'm not seeing history changes (including tab open/closes) being saved and then restored when I make a clean exit. If I wait long enough (15s?) they are saved

This repros without Fission as well, so getting it to work with SHiP doesn't have to be a priority, but it'll probably happen as part of bug 1572084 anyways.

Hi, I tried to get a manual regression range for this issue and I was able to reproduce the issue using the steps from Bug 1668882. The oldest Nightly build I was able to reproduce this issue on was a build from 02-Sep-2020, unfortunately any older builds I start with the fission.autostart and fission.sessionHistoryInParent enabled, Firefox starts to crash the moment I open a page like ESPN or CNN.com. In some older builds Firefox will start to crash even before reaching those pages after a restart.

I also tried to reproduce the issue without setting the fission preferences in about:config but I couldnt reproduce the issue without them.

Is there any other scenario we could try to reproduce the issue with?

Kashav said in comment 1 that this reproduces even without Fission. Rares, are you able to repro only with Fission? Please note that turning Fission pref on or off requires browser restart. And Nightly builds after Oct 3 do not require fission.sessionHistoryInParent pref (it gets enabled with fission.autostart). Builds before that require both prefs to be set followed by browser restart for them to take effect.

Yes, I was only able to reproduce this issue using the Fission preferences, and yes I did restart after each time, I was using the exact steps from this video https://bugzilla.mozilla.org/attachment.cgi?id=9180777 . With Fission I was able to reproduce this issue after a few restarts where the espn page would not load after restart, but without setting the Fisison preference the Espn page always loaded after restart, I only tried 10 to 15 times to restarts since with the fission prefs it usually hapens after 2 or 3.

Yes in older builds than october I was using both prefs and after restart it would crash either the tab or the entire Firefox, usually after Espn.com loads and the user accepts the cookies.

Kashav will look into this.

Will be fixed in bug 1572084.