The plugin that is trying to import RPi.GPIO (octoprint_smart_filament_sensor) is located at .octoprint.plugins. I am working on it.
I didn't install it. I copied it from my local development setup.
Problem is indicated in lines 255-271 of the octoprint.log
I asked how you installed it, I can see the error in the log, just no details of the plugin being installed. If you just placed it yourself in ~/.octoprint/plugins, then none of the dependencies that are listed in setup.py get installed alongside it. RPi.GPIO has never been installed by default in OctoPrint's virtual environment to the best of my knowledge.
Thanks, I understand.
In my previous setup RPi.GPIO was probably installed as a requirement for another plugin.
As I didn't install any of the plugins I had before, RPi is not there yet.
Thanks again for the warm welcome and sorry if my answer didn't exactly fit your question.
I did: octoprint_smart_filament_sensor
Still I do not know why this is useful. You can read the plugin name in the octoprint.log I attached, but it is a fork heavily modified from the original. So the name is meaningless without the code.
Because I do not know. I could check all the plugins I had installed and try to remember those I only tested and uninstalled in my previous setup and try to ascertain which one had the requirement, but I am not sure if this will provide any additional info to my question.
Since you are developing (or modifying) the plugin, I think the question to ask is how do I add a requirement for RPi.GPIO to the plugin so it will automagically be installed when the plugin is installed (I don't know the answer or I'd give it to you).
That would make sense that it turned up as a requirement previously - it happens commonly as well as dependencies aren't uninstalled if you remove a plugin.
When I'm developing plugins, I like to install them using pip in editable mode, so that the dependencies are installed at the same time as the plugin.
If you have your plugin project/git repo somewhere on your Pi, with OctoPrint's virtual environment activated (running ~/oprint/bin/activate), you can run pip install -e . inside your project's folder, and the setup.py file is processed by pip, and dependencies etc. are installed. To use with OctoPrint while developing it doesn't really make a functional difference, I feel like I just prefer it so I can develop outside the data folder.