There are two dependencies currently missing from Gramps during install, pygoocanvas and goocanvas. They're used by several of the Gramps plugins to render graphs.

Currently if a user has installed the graph plugins with the plugin manager, when starting the program there will be an error message about "grp.py", which is a pretty generic error and can just be clicked through. The program will work, even render the graphs, roughly. Running from a terminal will give the error namespace goocanvas not found. Installing the above packages fixes the problem.

Upstream bug report: https://gramps-project.org/bugs/view.php?id=10396

Checking their build instructions from their website it does not show it as a runtime dependency, which I can only assume is an oversight on their part. Most users will install the additional plugins from the plugin manager as the charts are extremely useful for grasping relationships. The graphs are of course optional, but seeing there's nothing in the error dialog to tell users how to fix the problem, it wouldn't hurt to add them as runtime dependencies so they're there if needed.