Configure should complain about missing qt5-graphicaleffects
P2 - Medium
S3 - Major
Since musescore 3.3, qt5-graphicaleffects (as Arch Linux calls it) is a hard dependency, as discussed in issue #296082: Palettes completely invisible and unusable in Ubuntu 18.04, using AppImage.
It is customary for the configure step to complain vigorously about missing dependencies, however the whole project configures and compiles happily without that package.
Comes up time and time again, as it leeds to e.g. the Snap version to not work. IMHO a bug and not a feature