REG[6.7 → 6.8]: generated qml type registration contains invalid include paths

Building the attached nonsense application runs into

[13/18 4.8/sec] Building CXX object CMakeFiles/appbrickman.dir/appbrickman_qmltyperegistrations.cpp.o
FAILED: ...
appbrickman_qmltyperegistrations.cpp:10:10: fatal error: 'base.h' file not found
   10 | #include <base.h>
      |          ^~~~~~~~
1 error generated.

That's mostly because some mechanism inserts the include of the Base class without the leading common/. Earlier versions didn't add that include, so I guess it's important. Well - at least not important enough, because I can safely remove it and it compiles.

It seems that I can get around the error by:

• Manually exporting the Base class to QML (it worked well up to now without doing that, do I have to?)
• Adding each subdirectory to the target_include_directories (where the party is crushed by time.h in the example)

Is there anything else I can do?