DISTRHO
Multiple Ildaeil instances crash Cardinal and DAW
The issue initially happened with LMMS and Ardour on a laptop/ Intel graphics/Ubuntu Studio 24.04.01 system. However, I was able to recreate it with LMMS on a desktop/NVIDIA graphics/Linux Mint LMDE 6 system.
On LMMS (lmms-1.3.0-alpha.1.102+g89fc6c9-linux-x86_64.AppImage), I opened the Cardinal synth via Carla Rack. Created a patch that included an Ildaeil/Vitalium instrument. Saved it and closed LMMS. Reopened the patch on LMMS and added an Ildaeil/Geonkick instrument. It worked without an issue. Saved it and closed LMMS. Reopened the LMMS project. I could hear the patch audio as soon as the project was launched. Opened Carla Rack GUI that contained the Cardinal patch. When I clicked the cog icon on Carla to open the Cardinal window, it crashed LMMS.
To test the issue on Ardour, I saved the same patch with only Ildaeil/Vitalium instrument as a vcv file.
On Ardour (8.4.0), I created a new session. Added Cardinal synth as a MIDI instrument. Opened the Cardinal window, opened the previously saved vcv file. It worked. I added an Ildaeil/Geonkick instrument. Still working. Closed the Cardinal window and saved the Ardour session and closed Ardour. When I reopened the Ardour session, I could hear the patch audio. When I tried to open the Cardinal window, it froze and then Ardour crashed.
So, nothing crashes when I add the second Ildaeil instance, or when I open the project that contains two Ildaeil instances. It only happens when I try to open the Cardinal window while two Ildaeil instances were used on a patch.
I tested it with Ildaeil/ZynAddSubFx as the second instance instead of Ildaeil/Geonkick, still happening on LMMS.
As Ildaeil is a 'mini-wrapper around Carla', I decided to test the issue with a Carla Plugin Host module instead of second Ildaeil instance. There is no issue. I am able to open the Cardinal window. Carla Plugin Host handles my need for adding outside synth plugins to Cardinal. I am not aware of any other uses of Ildaeil, so my issue is resolved.