sane is looking for non-existant document feeder
I use simple-scan on Manjaro KDE with an HP Envy 5542 aio printer / scanner.
After sane was upgraded to 1.2.1, simple-scan fails with the error message "Failed to scan - document feeder empty". There is no document feeder on my scanner. Downgrading sane to v. 1.1.1, everything works as expected.