Can't get tracktion engine Plugin Demo to find VST3 plugins on Linux [resolved]

I am running ubuntu 20.04. I am trying to run the plugin demo that ships with tracktion engine. When I click the plugins button it brings up an empty plugin list. I have a juce VST3 example plugin (just shows hello world in a window, it was the CMake plugin example from here) in ~/.vst3/ and ~/.vst/ but it doesnt seem to be finding any.

Additionally, I thought I would try loading this same vst in tracktion waveform but when it scans the juce example it gives an error:
" Note: the following files appeared to be plugin files, but failed to load correctly." and then it lists the .so file for the plugin.

The example plugin itself is located at ~/.vst3/Example.vst3/Contents/x86_64-linux/Example.so. I used the copy step feature to copy the plugin to this location with this directory structure.

This example plugin loads fine in Reaper. I also ran it in the juce audio plugin host and it worked there as well.

I tried digging through the plugin manager code in tracktion_engine but couldnt find any paths or anything in the scanning code. Where would I find that sort of thing? Is the tracktion engine plugin example even supposed to find external plugins? Also why cant waveform load this plugin?

Alright it looks like this was my fault after all. I redownloaded tracktion engine and made sure I cloned the dev branch, and after building the plugin example I was able to scan for VST3 plugins. I must have switched off the dev branch at some point earlier before I built the earlier plugin example that was not allowing me to scan for vst3s. Everything seems good now!

Where is the dev branch? I have the same problem and can only find the regular branch… Did you manage to load the plugin after the scan?

It’s on GitHub: https://github.com/Tracktion/tracktion_engine/tree/develop

Thanks