Bug 429921

Summary: Muon Discover hangs on Update process without errors and ability to cancel
Product: [Applications] Discover Reporter: Murz <MurzNN>
Component: UpdatesAssignee: Dan Leinir Turthra Jensen <leinir>
Status: RESOLVED WORKSFORME    
Severity: normal CC: aleixpol, echidnaman, joseph, mgolden, nate
Priority: NOR Keywords: efficiency-and-performance
Version First Reported In: unspecified   
Target Milestone: ---   
Platform: Ubuntu   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Murz 2020-12-02 12:02:45 UTC 
SUMMARY

On my system (Ubuntu 20.04) Muon Discover starts hanging on each Update process, without output of any errors, and with no ability to cancel the process. Here is screenshot: https://i.imgur.com/u7kvqV2.png

I wait already several hours, and nothing happens, nothing changed. CPU load is low, disk usage - same.

If I try to press "Cancel" - nothing happens, if try to close - Could not close Discover.

This happens every time when I try to install updates via Muon Discover, even after reboot, and after upgrading to Ubuntu 20.10 too. Via "apt dist-upgrade" all updates installs successfully.

How can I understand what goes wrong? And see the real source of this hanging problem?
Maybe I can view the raw output of apt/dpkg commands output?

SOFTWARE/OS VERSIONS
Operating System: Kubuntu 20.10
KDE Plasma Version: 5.19.5
KDE Frameworks Version: 5.74.0
Qt Version: 5.14.2
Kernel Version: 5.8.0-29-generic
OS Type: 64-bit
Processors: 4 × Intel® Core™ i3-4330 CPU @ 3.50GHz
Memory: 15,5 GiB of RAM
Graphics Processor: Mesa DRI Intel® HD Graphics 4600
Comment 1 Murz 2020-12-02 12:04:18 UTC 
Via `ps aux | grep -P 'apt|dpkg'` I don't see any active process in system.
Comment 2 Murz 2020-12-02 12:08:15 UTC 
Via strace for `/usr/bin/plasma-discover --mode update` process I see this output:
---
15:07:06.197061 restart_syscall(<... resuming interrupted read ...>) = 0 <0.148255>
15:07:06.345481 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 1000) = 0 (Timeout) <1.001085>
15:07:07.346685 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <0.999235>
15:07:08.346055 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <1.000075>
15:07:09.346334 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <0.999331>
15:07:10.345843 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 1000) = 0 (Timeout) <1.001089>
15:07:11.347128 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 998) = 0 (Timeout) <0.999228>
15:07:12.346694 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 1 ([{fd=5, revents=POLLIN}]) <0.506476>
15:07:12.853331 read(5, "\3\0\0\0\0\0\0\0", 16) = 8 <0.000020>
15:07:12.853456 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 492) = 0 (Timeout) <0.492528>
15:07:13.346071 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <1.000329>
15:07:14.346513 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <1.000045>
15:07:15.346675 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <1.000110>
15:07:16.346950 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <0.999600>
15:07:17.346703 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <0.999303>
15:07:18.346166 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 0 (Timeout) <0.999529>
15:07:19.345846 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 1000) = 1 ([{fd=5, revents=POLLIN}]) <0.901850>
15:07:20.247821 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000012>
15:07:20.247938 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 98) = 1 ([{fd=5, revents=POLLIN}]) <0.094774>
15:07:20.342799 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000025>
15:07:20.342890 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 3) = 1 ([{fd=5, revents=POLLIN}]) <0.001213>
15:07:20.344184 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000011>
15:07:20.344259 poll([{fd=3, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=3, revents=POLLOUT}]) <0.000046>
15:07:20.344346 writev(3, [{iov_base="\24\0\6\0001\1\0\0\306\1\0\0!\0\0\0\0\0\0\0\240\206\1\0", iov_len=24}], 1) = 24 <0.003796>
15:07:20.351043 futex(0x55c0f3df9a48, FUTEX_WAKE_PRIVATE, 1) = 1 <0.000040>
15:07:20.351137 futex(0x55c0f3df9a48, FUTEX_WAKE_PRIVATE, 1) = 0 <0.000009>
15:07:20.351301 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 0) = 1 ([{fd=5, revents=POLLIN}]) <0.000061>
15:07:20.351416 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000009>
15:07:20.351477 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 994) = 1 ([{fd=5, revents=POLLIN}]) <0.000941>
15:07:20.352478 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000009>
15:07:20.352568 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 993) = 1 ([{fd=5, revents=POLLIN}]) <0.003497>
15:07:20.356250 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000013>
15:07:20.356320 poll([{fd=3, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=3, revents=POLLOUT}]) <0.000012>
15:07:20.356368 writev(3, [{iov_base="\24\0\6\0001\1\0\0\225\1\0\0!\0\0\0\0\0\0\0\1\0\0\0", iov_len=24}], 1) = 24 <0.000015>
15:07:20.356424 futex(0x7ffcb0b35548, FUTEX_WAIT_PRIVATE, 0, NULL) = -1 EAGAIN (Ресурс временно недоступен) <0.000011>
15:07:20.356829 futex(0x55c0f3df9a48, FUTEX_WAKE_PRIVATE, 1) = 0 <0.000013>
15:07:20.356880 poll([{fd=3, events=POLLIN|POLLOUT}], 1, -1) = 1 ([{fd=3, revents=POLLOUT}]) <0.000011>
15:07:20.356926 writev(3, [{iov_base="\24\0\6\0001\1\0\0\225\1\0\0!\0\0\0\0\0\0\0\1\0\0\0", iov_len=24}], 1) = 24 <0.000015>
15:07:20.356972 futex(0x7ffcb0b35548, FUTEX_WAIT_PRIVATE, 0, NULL) = -1 EAGAIN (Ресурс временно недоступен) <0.000009>
15:07:20.357005 futex(0x55c0f3df9a48, FUTEX_WAKE_PRIVATE, 1) = 0 <0.000010>
15:07:20.357057 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 988) = 1 ([{fd=5, revents=POLLIN}]) <0.586020>
15:07:20.943697 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000018>
15:07:20.944021 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 402) = 1 ([{fd=5, revents=POLLIN}]) <0.000071>
15:07:20.944152 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000012>
15:07:20.944209 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 401) = 1 ([{fd=5, revents=POLLIN}]) <0.015812>
15:07:20.960103 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000015>
15:07:20.960219 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 385) = 1 ([{fd=5, revents=POLLIN}]) <0.007421>
15:07:20.967728 read(5, "\2\0\0\0\0\0\0\0", 16) = 8 <0.000011>
15:07:20.967818 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 378) = 1 ([{fd=5, revents=POLLIN}]) <0.008740>
15:07:20.976659 read(5, "\2\0\0\0\0\0\0\0", 16) = 8 <0.000019>
15:07:20.976786 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 369) = 1 ([{fd=5, revents=POLLIN}]) <0.006016>
15:07:20.982891 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000010>
15:07:20.982976 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 363) = 1 ([{fd=5, revents=POLLIN}]) <0.000014>
15:07:20.983038 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000011>
15:07:20.983090 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 362) = 1 ([{fd=5, revents=POLLIN}]) <0.008466>
15:07:20.991754 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000033>
15:07:20.992320 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 354) = 1 ([{fd=5, revents=POLLIN}]) <0.006580>
15:07:20.999671 read(5, "\2\0\0\0\0\0\0\0", 16) = 8 <0.000019>
15:07:20.999919 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 346) = 0 (Timeout) <0.346443>
15:07:21.346611 poll([{fd=5, events=POLLIN}, {fd=6, events=POLLIN}, {fd=10, events=POLLIN}, {fd=19, events=POLLIN}, {fd=31, events=POLLIN}], 5, 999) = 1 ([{fd=5, revents=POLLIN}]) <0.980410>
15:07:22.327344 read(5, "\1\0\0\0\0\0\0\0", 16) = 8 <0.000139>
----
Comment 3 Aleix Pol 2020-12-05 00:17:01 UTC 
Discover itself isn't doing the installing, it's PackageKit which is an external daemon. You can get logs from packagekit using "pkmon".

It's a weird issue, apt-based systems are among the best tested.
Comment 4 Murz 2020-12-08 16:34:41 UTC 
Seems this happens when Muon try to update Plasma Widgets, and can't download something. If I remove all widgets - apt packages are updates successfully via Muon.
But when try to install Plasma Widgets - got the error again: https://i.imgur.com/XpAWF1v.png

And pkmon show nothing:
---
$ pkmon
Transactions:
 [none]
daemon connected=1
network status=online
---
Does Muon use PackageKit for install Plasma Addons too, or make those jobs by himself?

And will be really useful to have some "Debug Logs" button to understand what is happening now. Even errors, that shown as popups, disappears on click (for example when I want to select text) and there are no ways to view them again, in some "Notifications history" list or logs.
Comment 5 Murz 2020-12-08 16:38:51 UTC 
Here are screenshot of some errors that shown when I try to update plasma addons (can't copy-paste them so here is screenshot): https://i.imgur.com/FSW61Yb.png
https://i.imgur.com/aKV6dEw.png
Comment 6 mgolden 2020-12-12 15:08:31 UTC 
Discover has been a separate component from Muon for some time now, so I am moving this ticket there.
Comment 7 Nate Graham 2025-09-23 18:35:22 UTC 
Thank you for the bug report, and I'm sorry we weren't able to look into it yet. Murz, a lot has changed since it was reported; can I ask you to see if this is still an issue with Plasma 6.4 or later? Thanks a lot.
Comment 8 Bug Janitor Service 2025-10-08 03:46:55 UTC 
🐛🧹 ⚠️ This bug has been in NEEDSINFO status with no change for at least 15 days. Please provide the requested information, then set the bug status to REPORTED. If there is no change for at least 30 days, it will be automatically closed as RESOLVED WORKSFORME.

For more information about our bug triaging procedures, please read https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging.

Thank you for helping us make KDE software even better for everyone!
Comment 9 Bug Janitor Service 2025-10-23 03:47:23 UTC 
🐛🧹 This bug has been in NEEDSINFO status with no change for at least 30 days. Closing as RESOLVED WORKSFORME.