BTW, thanks for these posts.
Sadly moz Dev is … Difficult to find info about things other than the function and how to call it. The source is all there, and some things are buried so deep in some topic or obscure inaccessible part of their site. But practical functionality and actual results of use are difficult to determine on my lonesome.
I use the tests on https://librewolf.net/docs/testing/ to do some things, but there are just so many unknowns.
Thanks again.
Found this :
https://askubuntu.com/a/1503216
GCC is the compiler. The code snippet in the link above sets the environment for the driver to use the compiler you have.