How can I check why a Qube won't start or crashes? Finding logs

User Support
1

I installed Element chat as outlined on their website. On a brand new Qubes system. I first created a template VM where it does install successfully (I launched it just to see if the app works). But when creating an App VM from it, that one first did not start (in the Qubes manager the rotating circle symbol that you normally only see briefly during start of a Qube remained on). How can I debug what is happening in such a case? Are there any logs anywhere?

After an update the Qube would magically start working. Maybe it got an apt update that made it work IDK. But next the Qube started crashing after being in use for about 1-2 minutes. That was majorly annoying. I did increase storage of that Qube but don’t think that was the issue. Also here it’d be great to know how to handle such issues in the future.

2

Plenty - in Qube Manager, right click on Offender and select “Logs” from
Menu

I never presume to speak for the Qubes team. When I comment in the Forum or in the mailing lists I speak for myself.
3

Thanks! I cannot reproduce the non-starting behavior of the VM but being able to debug the app crashes is helpful. In those logs I just see a bunch of logs

[2023-04-07 09:30:55] Debian GNU/Linux 11 my-chat hvc0
[2023-04-07 09:30:55] 
[2023-04-07 09:30:55] my-chat login: [2023-04-07 09:32:17] [   89.706524] show_signal: 8 callbacks suppressed
[2023-04-07 09:32:17] [   89.706533] traps: element-desktop[972] trap int3 ip:652f7bc303ff sp:7ffdcb36f440 error:0 in element-desktop[652f783a9000+7859000]
[2023-04-07 09:34:35] [  226.808378] traps: element-desktop[1239] trap int3 ip:5cab72a283ff sp:7ffd26f87360 error:0 in element-desktop[5cab6f1a1000+7859000]
[2023-04-07 09:53:25] [ 1357.020241] traps: element-desktop[1848] trap int3 ip:598565bb83ff sp:7fffe8b37440 error:0 in element-desktop[598562331000+7859000]
[2023-04-07 10:00:24] [ 1776.958282] traps: element-desktop[2099] trap int3 ip:62fdaf3193ff sp:7ffddbb89d80 error:0 in element-desktop[62fdaba92000+7859000]

I guess I need to check with the Element chat developers to find out what to check next. Still interesting that otherwise relatively stable software such as Element which does work well on all my other distros crashes on Qubes.