LADSPA plugins causing Segmentation Faults


A bunch of plugins have been causing segfaults, thus making ardour impossible to start on my system, even if I downgrade ardour. I am running EndevorOS with a 6.9.4-arch1-1 kernel. The plugins messing me up are:


Removing them let ardour run, hopefully someone out there having this problem can find this post useful, and that this issue gets rectified soon.

You need to provide more info for anyone to be able to figure out what your problem is.

Did you do anything particular right before it stopped working (like updating/upgrading the OS)?
What Ardour versions have you been trying and are they the official downloads from this site or ones that come with EndevorOS?
What crash messages do you get if you start Ardour from the command line?

Also note that alsa-plugins are not plugins used in Ardour and Calf is an LV2 plugin; not a LADSPA.
Calf won’t work in Ardout 8.4, or newer, from this site anyway, due to it using the deprecated GTK2 framework.


If I had to guess…

Some compiler flags used by your distro forces LADSPA plugins to free their descriptor info when the plugin is unloaded after scan. This will lead to a crash when Ardour scans those plugins at the start.

Please report this issue to your distro, ideally with a backtrace ( which will show the actual information.

PS. Here (debian) caps and mcp plugins works just fine, and swh-plugins the LV2 variant is preferable to begin with.

My apologies, this started when I upgraded the OS, with Ardour 8.6.0. I downloaded it from the official repos, and the messages are when I try to run ardour are:

Ardour8.6.0 (built using 8.6 and GCC version 13.2.1 20230801)
Ardour: [INFO]: Your system is configured to limit Ardour to 524288 open files
Ardour: [INFO]: Loading system configuration file /etc/ardour8/system_config
Ardour: [INFO]: Loading user configuration file /home/host/.config/ardour8/config
Ardour: [INFO]: CPU vendor: GenuineIntel
Ardour: [INFO]: CPU brand: Intel(R) Core™ i3 CPU 530 @ 2.93GHz
Ardour: [INFO]: Using SSE optimized routines
Ardour: [INFO]: Loading plugin meta data file /usr/share/ardour8/plugin_metadata/plugin_tags
Ardour: [INFO]: Loading plugin statistics file /home/host/.config/ardour8/plugin_metadata/plugin_stats
Ardour: [INFO]: add_lrdf_data ‘/home/host/.config/ardour8/rdf:/usr/share/ardour8/rdf:/usr/local/share/ladspa/rdf:/usr/share/ladspa/rdf’
Ardour: [INFO]: read rdf_file ‘file:///usr/share/ladspa/rdf/caps.rdf’
Segmentation fault (core dumped)

BTW I just tried running it with calf, mcp-plugins and the alsa-plugins downloaded and it works, woot woot.

That is a hint that the issue is the RDF (preset) file. Though without backtrace we cannot be certain. Here it also works just fine to load CAPS presets…

You can try to move the file /usr/share/ladspa/rdf/caps.rdf out of the way, and see if CAPS plugins work after that.

Could be related to libxml2 update.

Ardour: [INFO]: Lade Plugin-Statistik Datei /home/axel/.config/ardour8/plugin_metadata/plugin_stats
Ardour: [INFO]: add_lrdf_data '/home/axel/.config/ardour8/rdf:/usr/share/ardour8/rdf:/usr/local/share/ladspa/rdf:/usr/share/ladspa/rdf'
Ardour: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/ladspa.rdfs'
Ardour: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/ladspa-rubberband.rdf'
Ardour: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/swh-aux.rdf'
Ardour: [INFO]: read rdf_file 'file:///usr/share/ladspa/rdf/swh-plugins.rdf'
zsh: segmentation fault (core dumped)  ardour8

No issue with latest Ardour Nightly 8.6.267

Just had an update to libxml2 2.13.0-3. Ardour 8.6-1 starting again.

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Thanks for all the suggestions y’all, everything is working just fine now after updates.

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