This is a reproduction example for the issue 32970.

Run QGIS with installed plugin - on Ubuntu

If qgis is installed it might be sufficiant to execute

QGIS_PLUGINPATH=$(pwd)/ qgis

from within the repository.

Then go to the plugin menu and install Labeling Test and execute the plugin from the appearing icon in the toolbar.

If the PyQt libraries cannot be found it might be solved by starting qgis with the following command instead.

PATH=/usr/bin:${PATH} QGIS_PLUGINPATH=$(pwd)/ qgis

The PluginBuilder was used as a base start for this example.