Trying to fix a scanner problem (Brother DCP-110c scanner not working in Mint 18.1), and following this post that says to use
export SANE_DEBUG_DLL=128
scanimage -L
in order to look for errors of the form No such file or directory and copy the specified file at the specified location, I only got these errors:
[dll] load: trying to load `/usr/lib/x86_64-linux-gnu/sane/libsane-v4l.so.1'
[dll] load: couldn't open `/usr/lib/x86_64-linux-gnu/sane/libsane-v4l.so.1' (No such file or directory)
[dll] load: trying to load `/usr/lib/sane/libsane-v4l.so.1'
[dll] load: couldn't open `/usr/lib/sane/libsane-v4l.so.1' (No such file or directory)
[dll] load: couldn't find backend `v4l' (No such file or directory)
But these files seem absent (tested with locate)...