This is an upstream problem, I was hoping someone had an account with their bugtracker when working with the sane package. In the forum topic I have sometimes gotten my scanner in a state where it's confused - an error condition in the scanner. In this state, "scanimage -L" will report that the scanner can't be found - but this is incorrect - it found the scanner but found it to be unworkable. This error condition should be brought from the backend to the frontends as a hardware error condition, not a hardware not found problem. This threw me off for a long while worried my previously working scanner was no longer supported, until I found the debug switch that told me there's an error condition and told me the real issue. sane-find-scanner will always report that the scanner is there, which makes the debug very confusing. This is a feature enhancement and was meant for upstream... Not sure if anyone cares about it but just would like to post this somewhere :) Reproducible: Always Steps to Reproduce: 1. Get your avision scanner into an error state (adf jam, etc. and the "error" LED blinks on the scanner) 2. try to scan an image 3. Actual Results: SANE will report no scanner found Expected Results: SANE should report that an error occurred, and not report that there is no scanner I know this is affects the avision driver with the Xerox DocuMate 510. I don't know of any other scanners I can get into an error state and have this bug reproduced.
You can find the upstream entry here: https://alioth.debian.org/tracker/index.php?func=detail&aid=313961&group_id=30186&atid=410366 Closing this bug.