This project demonstrates bug 134374003.
It seems Android Gradle Plugin treats object libraries defined in CMakeLists when linked to with target_link_libraries
as if they were shared libraries and therefore as default targets for compilation. This leads to compilation failure:
Expected output file at … for target … but there was none
For a workaround, specify all targets explicitely (uncomment line 17 in app's build.gradle) or
use $<TARGET_OBJECTS:…>; however the latter does not propagate compiler and linker flags from the object library.