SUMMARY When I close Discover (by clicking the "X" in the upper right-hand corner) after performing "Update all", Discover often reports a segmentation fault. A backtrace could not be generated. STEPS TO REPRODUCE 1. Open Discover (generally by clicking on the "updates available" notification). 2. Perform "update all" 3. Wait for "all up to date" message. 4. Click on "X" in the upper right-hand corner. OBSERVED RESULT Discover closes the UI but a segmentation fault crash report displays. When I click on the tab "developer information", the animated "wait" symbol displays. When I try to complete the bug reporting process, it says that a backtrace could not be generated. EXPECTED RESULT Discover closes gracefully. SOFTWARE/OS VERSIONS Linux/KDE Plasma: Ubuntu Studio 22.04.1 (available in About System) KDE Plasma Version: 5.24.6 KDE Frameworks Version: 5.98.0 Qt Version: 5.15.3 ADDITIONAL INFORMATION
> When I try to complete the bug reporting process, it says that a backtrace could not be generated. I'm afraid that if something crashed, we need a backtrace of it so we can figure out what's going on. You may be able to use `coredumpctl` to get one; see https://community.kde.org/Guidelines_and_HOWTOs/Debugging/How_to_create_useful_crash_reports. If we can't see a backtrace, then sadly this bug report isn't actionable.
Sorry for the slow response. I haven't yet succeeded in creating a backtrace. I find the guidelines you referred me to complex and opaque. It isn't clear to me which debug symbols I should look for. Since Ubuntu Studio uses KDE, should I follow the Kubuntu link (https://wiki.ubuntu.com/Debug%20Symbol%20Packages)? This contains a further link to https://help.ubuntu.com/community/Repositories/Ubuntu, which, ironically, links back to itself ("For Kubuntu please see Kubuntu repository management.") but doesn't indicate what repository I need to add to get debug symbols. IAC, it may help to know that the crash seems to occur only when I try to close Discover shortly (< 10 sec.) after it has finished updating (or *appears* to be finished). Perhaps Discover is still busy with some cleanup work which "close" fails to wait for.
You might be able to contact the Ubuntu Studio people and ask for help. It's a shame that the instructions have to be complex, but the procedure varies by distro, and unfortunately some don't make it so simple.
Dear Bug Submitter, This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information as soon as possible and set the bug status as REPORTED. Due to regular bug tracker maintenance, if the bug is still in NEEDSINFO status with no change in 30 days the bug will be closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging If you have already provided the requested information, please mark the bug as REPORTED so that the KDE team knows that the bug is ready to be confirmed. Thank you for helping us make KDE software even better for everyone!
I have attempted to find debugging symbols for Discover by adding the following repositories to my Software Sources: >> deb http://ddebs.ubuntu.com jammy main restricted universe multiverse deb http://ddebs.ubuntu.com jammy-updates main restricted universe multiverse deb http://ddebs.ubuntu.com jammy-security main restricted universe multiverse deb http://ddebs.ubuntu.com jammy-proposed main restricted universe multiverse << as recommended in this thread: >> https://askubuntu.com/questions/487222/how-to-install-debug-symbols-for-installed-packages << However, I was then prompted to refresh the cache, which produced the following error message: >> Could not refresh cache pk-client-error-quark: E: The repository 'http://ddebs.ubuntu.com jammy-security Release' does not have a Release file. W: Updating from such a repository can't be done securely, and is therefore disabled by default. W: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://ddebs.ubuntu.com jammy Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C8CAB6595FDFF622 E: The repository 'http://ddebs.ubuntu.com jammy Release' is not signed. W: Updating from such a repository can't be done securely, and is therefore disabled by default. W: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://ddebs.ubuntu.com jammy-updates Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C8CAB6595FDFF622 E: The repository 'http://ddebs.ubuntu.com jammy-updates Release' is not signed. W: Updating from such a repository can't be done securely, and is therefore disabled by default. W: See apt-secure(8) manpage for repository creation and user configuration details. W: GPG error: http://ddebs.ubuntu.com jammy-proposed Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY C8CAB6595FDFF622 E: The repository 'http://ddebs.ubuntu.com jammy-proposed Release' is not signed. (319) << I have performed the recommended "sudo apt install ubuntu-dbgsym-keyring" Unsurprisingly, I am still unable to find or install Discover debug symbols to enable a backtrace of the problem. Unless or until someone can tell me how to install the needed debug symbols, I will be unable to provide the requested information.
P.S: My previous theory was incorrect. The crash occurs every time I close Discover after performing "Update All", regardless of how long I wait before closing Discover.
It's a shame getting a proper backtrace is so difficult on Ubuntu. Nevertheless, that's what we need to proceed. The right place to ask for help is an Ubuntu-specific forum/venues/support channel/etc. The people there can help you set it up properly. We don't all use Ubuntu here (in fact few of us do) and probably can't help you with distro-specific issues in general.
I still haven't managed to install debug symbols, but I have observed that the crash only occurs if I try to close Discover while it is still on the "Updates" page/tab (which says "Up to date" instead of "Updates" once the updates are completed). If I switch to the "Applications" page/tab before closing Discover, no crash results. Hope this helps.
Created attachment 154473 [details] Screenshot of result from attempting backtrace
This bug has been in NEEDSINFO status with no change for at least 30 days. The bug is now closed as RESOLVED > WORKSFORME due to lack of needed information. For more information about our bug triaging procedures please read the wiki located here: https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging Thank you for helping us make KDE software even better for everyone!