The combination of adding a udev rule to ignore all Canon cameras, and commenting out the section for my camera in 20-libgphoto2-6.hwdb seems to have worked.
Glad to hear you got it working.
Maybe checking that file could be added to the documentation? There's a ton of Canon cameras in there.
Which documentation? (not being snarky, it's pretty scattered)
You are certainly welcome to to add to the CHDK wiki, and I'm happy to take suggestions for the chdkptp install.txt / wiki page.
I admit I tend to be hand-wavy about the linux stuff because it's distro specific, not well documented upstream, and I don't understand it that well myself.
