Transmission freezes when adding second magnet in Ubuntu 19.04

Thank you for your bug report. What is a magnet? Could you add your journalctl log to the bug after getting the issue?

Magnet link is a kind of torrent without the need of downloading a torrent file (you just add link and it starts downloading).
I tried to use journalctl and this seems to be where the problem is:

Thg 4 24 19:13:32 DINGO transmission-gt[3579]: g_object_set_data: assertion 'G_IS_OBJECT (object)' failed
Thg 4 24 19:13:32 DINGO transmission-gt[3579]: gdk_window_get_window_type: assertion 'GDK_IS_WINDOW (window)' failed
Thg 4 24 19:13:32 DINGO transmission-gt[3579]: _gtk_widget_captured_event: assertion 'WIDGET_REALIZED_FOR_EVENT (widget, event)' failed
Thg 4 24 19:13:32 DINGO transmission-gt[3579]: _gtk_widget_captured_event: assertion 'WIDGET_REALIZED_FOR_EVENT (widget, event)' failed
Thg 4 24 19:13:32 DINGO transmission-gt[3579]: _gtk_widget_captured_event: assertion 'WIDGET_REALIZED_FOR_EVENT (widget, event)' failed

Could you give an url example to test the issue?

The issue seems to only appear when directly clicking link from browser. You can go to https://nyaa.si/ in the "Link" column, there's U-like symbols, those are magnet link. Just click it.

Thanks

Status changed to 'Confirmed' because the bug affects multiple users.

Using the steps described it doesn't hang there. Could you get a backtrace using the instructions on https://wiki.ubuntu.com/Backtrace#Already_running_programs ?

This is the backtrace of the bug.

This is the video of the whole process in case you need it.

Thanks, it's a bit weird that ctrl-C in gdb doesn't work and that you don't get a prompt back after killing the process. Could you try by exiting transmission and doing
$ gdb transmission-gtk
(gdb) r <enter>
... get the issue
(gdb) <Ctrl-C>
(gdb) t a a bt

This is the output after (gdb) t a a bt:

Thread 13 (Thread 0x7fffcdffb700 (LWP 7985)):
#0 0x00007ffff6bc4729 in __GI___poll (fds=0x555555f4b270, nfds=1, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007ffff7426cb6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007ffff7426ddc in g_main_context_iteration () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007ffff7fc5ffd in ?? () from /usr/lib/x86_64-linux-gnu/gio/modules/libdconfsettings.so
#4 0x00007ffff744f98d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#5 0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#6 0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 11 (Thread 0x7fffceffd700 (LWP 7983)):
#0 syscall () at ../sysdeps/unix/sysv/linux/x86_64/syscall.S:38
#1 0x00007ffff7471b9a in g_cond_wait_until () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#2 0x00007ffff73f80c1 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#3 0x00007ffff73f8681 in g_async_queue_timeout_pop () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#4 0x00007ffff74503f1 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
--Type <RET> for more, q to quit, c to continue without paging--
#5 0x00007ffff744f98d in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0
#6 0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#7 0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 8 (Thread 0x7fffcffff700 (LWP 7972)):
#0 0x00007ffff6bc4729 in __GI___poll (fds=0x7fffc8007080, nfds=3, timeout=-1) at ../sysdeps/unix/sysv/linux/poll.c:29
#1 0x00007fffe08359f1 in ?? () from /lib/x86_64-linux-gnu/libpulse.so.0
#2 0x00007fffe0827260 in pa_mainloop_poll () from /lib/x86_64-linux-gnu/libpulse.so.0
#3 0x00007fffe08278ae in pa_mainloop_iterate () from /lib/x86_64-linux-gnu/libpulse.so.0
#4 0x00007fffe0827960 in pa_mainloop_run () from /lib/x86_64-linux-gnu/libpulse.so.0
#5 0x00007fffe0835939 in ?? () from /lib/x86_64-linux-gnu/libpulse.so.0
#6 0x00007fffe07d5788 in ?? () from /usr/lib/x86_64-linux-gnu/pulseaudio/libpulsecommon-12.2.so
#7 0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#8 0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95
--Type <RET> for more, q to quit, c to continue without paging--

Thread 6 (Thread 0x7fffe3fff700 (LWP 7969)):
#0 0x00007ffff6cb1440 in __GI___nanosleep (requested_time=0x7fffe3ffe800, remaining=0x0) at ../sysdeps/unix/sysv/linux/nanosleep.c:28
#1 0x00005555555b5c66 in tr_wait_msec ()
#2 0x00005555555b2772 in ?? ()
#3 0x000055555559f63a in ?? ()
#4 0x00007ffff6ca7182 in start_thread (arg=<optimized out>) at pthread_create.c:486
#5 0x00007ffff6bd0b1f in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

Thread 5 (Thread 0x7ffff0b4f700 (LWP 7968)):
#0 0x00007ffff6bd0e3f in epoll_wait (epfd=12, events=0x7fffdc000e20, maxevents=32, timeout=39) at ../sysdeps/unix/sysv/linux/epoll_wait.c:30
#1 0x00007ffff71b02c5 in ?? () from /lib/x86_64-linux-gnu/libevent-2.1.so.6
#2 0x00007ffff71a6114 in event_base_loop () from /lib/x86_64-linux-gnu/libevent-2.1.so.6
#3 ...

The backtrace doesn't have anything obviously wrong (it lacks debug symbols also but unsure it would make a difference), setting back to "New" until someone has time to poke at it more, unsure why it doesn't happen here and is so consitent for you though

(do you use any non default option maybe?)

I don't use any non default option. I remember this problem suddenly happened to me one day during the time of ubuntu 19.04 beta and it's still there when I freshly installed ubuntu 19.04 stable.

Could you maybe also report it to the upstream code writers on https://github.com/transmission/transmission ? They might have a better clue about the issue