I wrote a toy plugin for QGIS-3 (2.99 Ubuntu 16.04), which worked for quite a while. But after a recent upgrade, the plugin disappeared from the QGIS toolbar while the rest of QGIS seem to be working fine.
I have checked that the
~/.qgis3/python/plugins/ folder is still present. I tried to use
pb_tool deploy to re-install the plugin. But the plugin still wouldn't show in the toolbar.
Does someone know what could have gone wrong?