Extra configuration for Evince

If xdg-open works, but Evince still refuses to open point and click links due to denied permissions, you might need to change the Apparmor profile of Evince which controls the kind of actions Evince is allowed to perform.

For Ubuntu, the process is to edit the file /etc/apparmor.d/local/usr.bin.evince and append the following lines:

# For Textedit links
/usr/local/bin/lilypond-invoke-editor Cx -> sanitized_helper,

After adding these lines, call

sudo apparmor_parser -r -T -W /etc/apparmor.d/usr.bin.evince

Now Evince should be able to open point and click links. It is likely that similar configurations will work for other viewers.