From time to time I block on message "Failed to validate broken face" when I launch a protrusion from a sketch. My basically understanding is that somewhere remains an open figure, for instance 2 lines ended by 2 points without constraint. The main reason for this error are open vertices ...

Not for me. Here is the script I use to install and try building freecad on Debian 10 mkdir ~/src cd ~/src sudo apt update -y git clone https://github.com/FreeCAD/FreeCAD.git sudo apt build-dep freecad -y sudo apt install cmake cmake-gui libboost-date-time-dev libboost-dev libboost-filesystem-dev li...