Flasher dependencies
I've seen at least 2 people follow the instructions from https://developer.puri.sm/Librem5/Development_Environment/Phone/Troubleshooting/Reflashing_the_Phone.html and getting stuck on Python dependencies.
There's a line that seems to be ignored:
Make sure you have installed all python dependencies
sudo apt build-dep .
.
It could be easier to make a note that all this is available in the librem5-host package on PureOS. I'm also not sure if buid-dep is available by default.