Hello Absinthe,
I did the same thing with 2.2.0-rc1. Initially I installed it to /usr/ as you would find with LibreCAD installed from the repository;
librecad, ttf2lff -> /usr/bin/librecad
./resources/* -> /usr/share/librecad/
./resources/plugins/* -> /usr/lib/librecad/
However, after installing a couple of applications from their respective sites, Firefox and LibreOffice, I found the the correct location for
user installed applications is
/opt/ (also see
/opt/ vs /usr/local/). I cleaned up what I had done previously and ended up doing a manual install to /opt/:
Manually installed from the ./unix/ directory to /opt/librecad/:
sudo mkdir /opt/librecad
sudo cp -R * /opt/librecad
sudo chmod -R ug+rX /opt/librecad/*
Launch LibreCAD and configure paths via Options -> Application Preferences, Paths tab:
Translations: /opt/librecad/resources/qm
Hatch Patterns: /opt/librecad/resources/patterns
Fonts: /opt/librecad/resources/fonts
Part Libraries: /opt/librecad/resources/library
Both ways work (including the plugins), but in the end the /opt/ method might be easier to maintain.