Tell Launchpad what DEB_BUILD_OPTIONS to use when building PPA package
Solution 1:
The PPAs do not have a way to specify an environment variables (including DEB_BUILD_OPTIONS) unfortunately. Until they do, you will need to edit the debian/rules file and set it manually yourself near the top (but not the first line if it uses a "#!"):
DEB_BUILD_OPTIONS=nodocs
Optionally, just find the section of the rules file that looks for "nodocs" and change it to do what you need it to do.
Solution 2:
Set it in your debian/rules file.