Error with LADSPA plugins: "plugin has no descriptor function"

Hello all :slight_smile:

I have been trying to install Argotlunar and Hypercyclic as Ardour plugins without success. I keep getting there errors:

[ERROR]: LADSPA: module "/usr/lib/ladspa/argotlunar.so" has no descriptor function.
[ERROR]: 'ladspa_descriptor': /usr/lib/ladspa/argotlunar.so: undefined symbol: ladspa_descriptor
[ERROR]: LADSPA: module "/usr/lib/ladspa/hypercyclic.so" has no descriptor function.
[ERROR]: 'ladspa_descriptor': /usr/lib/ladspa/hypercyclic.so: undefined symbol: ladspa_descriptor

The .so files are under /usr/lib/ladspa along with the other ones (I am on Ubuntu 18,04) but every time I make Ardour scan for plugins I get the error above.

Weirdly, I am able to launch Hypercyclic with their executable, just not with Ardour.

So I took a brief look at the build process for Argotlunar and the websites for both, it doesn’t appear these are LADSPA plugins, they appear to be VSTs. Did you get LADSPA versions of these somewhere or are these in fact VSTs? If the latter they probably shouldn’t be in /use/lib/ladspa but instead be in a directory that Ardour searches for VSTs in. As you can see here https://manual.ardour.org/working-with-plugins/getting-plugins/ there are a couple of default locations as well you could try:

Linux VST (LXVST) plugins are distributed as shared library files. They are typically installed in /usr/lib/lxvst, /usr/local/lib/lxvst or a directory mentioned in the local LXVST_PATH environment variable.

The error you are seeing is because Ardour is trying to load them like a LADSPA plugin, because they are in the location for LADSPA plugins, but not finding the LADSPA functions required for those plugins, which is understandable for a VST.

    Seablade