firefox is not using system libwebp
Brendan L reported on -dev that there is a --with-system-webp option to link agaisnt the system library.
In mitigation for not checking if it was using the system version (it was not) I have multiple pleas:
· incompetence · it was new in this version
At the moment my development machine is busy building qtwebengine-5.12.1, I'll get to this later.