in src:glx-alternatives I have a script to generate
debian/glx-alternative-mesa.triggers, but unfortunately I have to run it
explicitly from debian/rules, I cannot just make it executable and name
it debian/glx-alternative-mesa.triggers as it works with other files.
dh_installdeb also generates 'Pre-Depends: dpkg (>> ...)', for having
It might be useful to something similar for triggers, according to
deb-triggers(5) this must be 'Pre-Depends: dpkg (>= 1.16.1)' for
-noawait triggers and 'Pre-Depends: dpkg (>= 1.17.21)' for -await