Check if b2g supports a particular locale font-wise.
You'll need to update the moztt and base submodules to the revisions you test, and run the script as
python buildfonts.py path/to/mozilla/repo ab-CD
The tools relies on font-config to do the heavy lifting. The tool is currently only catching the Regular font weights, etc.
If you're running the tool for the first time, make sure to get the submodule repositories,
git submodule update --init