Canon LiDE 120 Scanner vs. Sane vs. Networking: FAIL

The Canon LiDE 120 scanner on Mary’s desk gets considerable use by both of us, until a recent update of something killed network access to it. The usual searches revealed comments suggesting the sane scanner program has deliberately disabled network access to USB scanners which use the net back end, apparently to prevent loops when one instance shares a networked USB scanner already shared by another instance.

I have no clue how all that works, nor why the change has apparently taken half a dozen years to reach our scanner.

The workaround required downgrading sane on the “server” PC (the one with the Canon scanner) to the most recent version that doesn’t enforce the prohibition:

sudo pacman -U /var/cache/pacman/pkg/sane-1.1.1-2-x86_64.pkg.tar.zst

And preventing further upgrades with a stanza in /etc/pacman.conf:

IgnorePkg = sane

The pamac GUI interface now shows sane as eligible for an upgrade, then reports that it won’t do the deed. That’s survivable.

At some point, not updating the sane package will cause other problems. Perhaps by then we’ll have moved the hulking Epson ET-3830 printer/scanner upstairs and can recycle the Canon scanner.