Be more verbose about missing optional dependencies
Right now when you build a project with optional dependencies that you don't have installed, this information is buried in the CMake log which is not visible unless you go hunting for it.
This can cause you to run an app from your built-from-source version, but with various plugins and optional libraries from the distro-provided version, because you didn't have the build deps to build those optional features yourself. This has caused somewhat significant problems for me multiple times in the form of crashes that others could not reproduce, and features or tested merge requests that did not work properly because I did not build the optional bits which were a part of the features in question.
It would be nice if kdesrc-build could be more proactive about alerting you to this by printing information about a project's missing deps to its standard output somewhere.