Debugging segmentation fault

I’ve been having some weird behavior with my current project. Every time I start jack and open this session, I get the segmentation fault error. After one or two tries, it usually starts and works fine from there, though.

At this point I have bunch of plugins already… Is there a way to debug this without removing the plugins one by one? Most of the plugins are OvertoneDSPs, but also some LSP, and Calf.

Since Paul often suggests Calf causes problems, I tried removing all Calf plugins (in a snapshot), but the problem persists.

Here is the terminal output of an instance:

$ ardour 
Fontconfig warning: line 5: unknown element "its:rules"
Fontconfig warning: line 6: unknown element "its:translateRule"
Fontconfig error: line 6: invalid attribute 'translate'
Fontconfig error: line 6: invalid attribute 'selector'
Fontconfig error: line 7: invalid attribute 'xmlns:its'
Fontconfig error: line 7: invalid attribute 'version'
Fontconfig warning: line 9: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/10-hinting-slight.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/10-hinting-slight.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/10-hinting-slight.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/10-hinting-slight.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/10-hinting-slight.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/10-hinting-slight.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/10-hinting-slight.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/10-scale-bitmap-fonts.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/11-lcdfilter-default.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/20-unhint-small-vera.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/30-metric-aliases.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/30-metric-aliases.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/30-metric-aliases.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/30-metric-aliases.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/40-nonlatin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/40-nonlatin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/40-nonlatin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/40-nonlatin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/45-generic.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/45-generic.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/45-generic.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/45-generic.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/45-latin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/45-latin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/45-latin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/45-latin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/49-sansserif.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/49-sansserif.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/49-sansserif.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/49-sansserif.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/50-user.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/50-user.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/51-local.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/51-local.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/51-local.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/51-local.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/60-generic.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/60-generic.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/60-generic.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/60-generic.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/60-latin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/60-latin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/60-latin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/60-latin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/65-fonts-persian.conf", line 34: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/65-fonts-persian.conf", line 35: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 35: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 35: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 36: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/65-fonts-persian.conf", line 36: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/65-nonlatin.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/65-nonlatin.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/65-nonlatin.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/65-nonlatin.conf", line 8: unknown element "description"
Fontconfig warning: "/etc/fonts/conf.d/69-unifont.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/69-unifont.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/69-unifont.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/80-delicious.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/80-delicious.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/80-delicious.conf", line 6: invalid attribute 'version'
Fontconfig warning: "/etc/fonts/conf.d/90-synthetic.conf", line 4: unknown element "its:rules"
Fontconfig warning: "/etc/fonts/conf.d/90-synthetic.conf", line 5: unknown element "its:translateRule"
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 5: invalid attribute 'translate'
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 5: invalid attribute 'selector'
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 6: invalid attribute 'xmlns:its'
Fontconfig error: "/etc/fonts/conf.d/90-synthetic.conf", line 6: invalid attribute 'version'
Fontconfig error: Cannot load default config file
bind txt domain [gtk2_ardour5] to /opt/ardour/share/locale
Ardour5.12.0 (built using 5.12 and GCC version 5.2.1 20150903)
ardour: [INFO]: Your system is configured to limit Ardour to only 1048576 open files
ardour: [INFO]: Loading system configuration file /opt/ardour/etc/system_config
ardour: [INFO]: Loading user configuration file /home/finotti/.config/ardour5/config
ardour: [INFO]: CPU vendor: GenuineIntel
ardour: [INFO]: AVX-capable processor
ardour: [INFO]: CPU brand: Intel(R) Core(TM) i7-4771 CPU @ 3.50GHz
ardour: [INFO]: Using SSE optimized routines
Cannot xinstall SIGPIPE error handler
ardour: [INFO]: Loading default ui configuration file /opt/ardour/etc/default_ui_config
ardour: [INFO]: Loading user ui configuration file /home/finotti/.config/ardour5/ui_config

(ardour-5.12.0:30936): Gtk-WARNING **: Unable to locate theme engine in module_path: "adwaita",

(ardour-5.12.0:30936): Gtk-WARNING **: Unable to locate theme engine in module_path: "adwaita",
Color shuttle bg not found
ardour: [INFO]: Loading color file /opt/ardour/share/themes/dark-ardour.colors

(ardour-5.12.0:30936): Gtk-WARNING **: Unable to locate theme engine in module_path: "adwaita",

(ardour-5.12.0:30936): Gtk-WARNING **: Unable to locate theme engine in module_path: "adwaita",
ardour: [INFO]: Loading ui configuration file /opt/ardour/etc/clearlooks.rc
ardour: [INFO]: Loading ui configuration file /opt/ardour/etc/clearlooks.rc
Found 3 along /home/finotti/.config/ardour5/templates:/opt/ardour/share/templates
run dialog
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
RemoteVSTClient: all cache files are up-to-date, not running scanner
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
RemoteVSTClient: all cache files are up-to-date, not running scanner
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
convolution: samplerate mismatch preset:48000 host:44100
Scanning folders for bundled LV2s: /opt/ardour/lib/LV2
Set cursor set to default
Editor didn't find Editor/start-range in editor
Editor didn't find Editor/finish-range in editor
Editor didn't find Editor/jump-backward-to-mark in editor
Editor didn't find Region/split-region in editor
Editor didn't find Editor/jump-forward-to-mark in editor
Editor didn't find Editor/add-location-from-playhead in editor
Editor didn't find Editor/alternate-add-location-from-playhead in editor
Editor didn't find Editor/start-punch-range in editor
Editor didn't find Editor/finish-punch-range in editor
Editor didn't find Editor/addExistingAudioFiles in editor
Editor didn't find Editor/remove-location-from-playhead in editor
Editor didn't find Editor/alternate-remove-location-from-playhead in editor
Editor didn't find Editor/alternate-jump-backward-to-mark in editor
Editor didn't find Editor/alt-finish-range in editor
Editor didn't find Editor/alternate-jump-forward-to-mark in editor
Editor didn't find Editor/alt-start-range in editor
Editor didn't find Editor/nudge-next-forward in editor
Editor didn't find Editor/nudge-next-backward in editor
Editor didn't find Editor/start-loop-range in editor
Editor didn't find Editor/finish-loop-range in editor
Editor didn't find Editor/nudge-playhead-backward in editor
Editor didn't find Editor/nudge-playhead-forward in editor
Editor didn't find Editor/playhead-backward-to-grid in editor
Editor didn't find Editor/playhead-forward-to-grid in editor
Editor didn't find Editor/start-range in editor
Editor didn't find Editor/finish-range in editor
Editor didn't find Editor/jump-backward-to-mark in editor
Editor didn't find Region/split-region in editor
Editor didn't find Editor/jump-forward-to-mark in editor
Editor didn't find Editor/add-location-from-playhead in editor
Editor didn't find Editor/alternate-add-location-from-playhead in editor
Editor didn't find Editor/start-punch-range in editor
Editor didn't find Editor/finish-punch-range in editor
Editor didn't find Editor/addExistingAudioFiles in editor
Editor didn't find Editor/remove-location-from-playhead in editor
Editor didn't find Editor/alternate-remove-location-from-playhead in editor
Editor didn't find Editor/alternate-jump-backward-to-mark in editor
Editor didn't find Editor/alt-finish-range in editor
Editor didn't find Editor/alternate-jump-forward-to-mark in editor
Editor didn't find Editor/alt-start-range in editor
Editor didn't find Editor/nudge-next-forward in editor
Editor didn't find Editor/nudge-next-backward in editor
Editor didn't find Editor/start-loop-range in editor
Editor didn't find Editor/finish-loop-range in editor
Editor didn't find Editor/nudge-playhead-backward in editor
Editor didn't find Editor/nudge-playhead-forward in editor
Editor didn't find Editor/playhead-backward-to-grid in editor
Editor didn't find Editor/playhead-forward-to-grid in editor
Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for FC70
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Do *not* Emulate VST Bypass Port for Console5Buss
Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for FC70
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Do *not* Emulate VST Bypass Port for Console5Buss
Emulate VST Bypass Port for FC70
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Emulate VST Bypass Port for PTC-2A
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Emulate VST Bypass Port for FC70
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Emulate VST Bypass Port for AF210
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lo server running on 14690
lo server running on 15387
lo server running on 16577
Do *not* Emulate VST Bypass Port for Console5Buss
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for AF210
effSetBypass 0
Do *not* Emulate VST Bypass Port for Console5Buss
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for FC70
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lo server running on 15139
lo server running on 14661
lo server running on 15239
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for AF210
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lo server running on 11467
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for AF210
effSetBypass 0
Emulate VST Bypass Port for FC70
effSetBypass 0
Emulate VST Bypass Port for GTriChorus
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Emulate VST Bypass Port for AF210
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Segmentation fault

I’m using the latest version (5.12) from KXStudio in Debian Sid, if this is relevant.

Any help would be greatly appreciated.

http://ardour.org/debugging_ardour

To do it properly requires a debug build of Ardour.

However, in your case, you should probaly start with what we call safe-mode, which disables all plugins without removing them. It’s an option at the bottom of the session selector dialog that shows up when you start Ardour.

It seems it was the LSP Plugins (the IR/Reverb one, apparently). The random segmentation faults at start up seemed to have stopped, but when I tried to edit the parameters of the plugin, it would freeze or crash Ardour.

Here is the GDB log I could get after a crash: https://pastebin.com/Si2YrmPY

(I will try to contact LSP too.)

I don’t know if it is worth anything, but here is the log of a previous segmentation fault on start up. Unfortunately, I had missed the part of disabling Real Time (it was checked) and setting client timeout variable to 5000 (it was 0, I think).

https://pastebin.com/5aRAga53

The bug certainly appears to be in the LSP code. There’s not much that we can do about that, unfortunately. It would be useful to have the output from just a few lines earlier, to confirm which thread the crash occured in.