Crash + core dump

Installation & Configuration Linux
#1

Command line output

Set buffering params to 262144|131072|10|10
Skip explicit buffer seconds, preset in use
Skip explicit buffer seconds, preset in use
fluidsynth: warning: No preset found on channel 9 [bank=128 prog=0]
fluidsynth: warning: No preset found on channel 9 [bank=128 prog=0]
actually writing state to /home/cyrus/Desktop/thingamagig_songs/thingamagig-the_strokes-you_only_live_once/thingamagig-the_strokes-you_only_live_once.tmp
renaming state to /home/cyrus/Desktop/thingamagig_songs/thingamagig-the_strokes-you_only_live_once/thingamagig-the_strokes-you_only_live_once.ardour
ardour-5.12.0: /usr/include/boost/smart_ptr/shared_ptr.hpp:734: typename boost::detail::sp_member_access::type boost::shared_ptr::operator->() const [with T = Evoral::PatchChangeEvoral::Beats; typename boost::detail::sp_member_access::type = Evoral::PatchChangeEvoral::Beats*]: Assertion `px != 0’ failed.
Aborted (core dumped)

Core dump /var/log/apport.log

ERROR: apport (pid 2654) Wed Jul 3 08:50:35 2019: called for pid 2611, signal 6, core limit 0, dump mode 1
ERROR: apport (pid 2654) Wed Jul 3 08:50:35 2019: executable: /home/cyrus/Ardour-5.12.0/build/gtk2_ardour/ardour-5.12.0 (command line “/home/cyrus/Ardour-5.12.0/gtk2_ardour/…/build/gtk2_ardour/ardour-5.12.0”)
ERROR: apport (pid 2654) Wed Jul 3 08:50:35 2019: executable does not belong to a package, ignoring

Any thoughts on the cause? Session is two audio tracks, one empty and one with gxAmplifier-x. Three tracks of reasonablesynth midi, one track of a-Fluid + /usr/sounds/sf2/FluidGM.sf2.

#2

What were you doing at the time of this crash?

Evoral::PatchChange … px !=0 – would indicate an invalid MIDI patch-change on a track being played or displayed. Impossible to say without a backtrace though.

In case of a self-built the best is to start the debug-session directly from the source-tree:

cd /home/cyrus/Ardour-5.12.0/gtk2_ardour/
./ardbg
(gdb) run
## make ardour crash, gdb prompt returns
(gdb) thread apply all bt
# there will be several pages, be sure you get them all

now open a ticket on http://tracker.ardour.org/ and attach the complete output of the above debug session.

see also https://ardour.org/debugging_ardour

Ideally we’ll also move this discussion to the bug-tracker. A web-forum is not great at keeping track of issues.