These are the packages that would be merged, in order:

Calculating dependencies ...

!!! Problem resolving dependencies for =dev-lang/spark-2024.01.11-r2
 done!
Dependency resolution took 0.83 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=dev-lang/spark-2024.01.11-r2" has unmet requirements.
- dev-lang/spark-2024.01.11-r2::gentoo USE="-doc" ADA_TARGET="gcc_15 -gcc_12 -gcc_13 -gcc_14 (-gcc_16)"

  The following REQUIRED_USE flag constraints are unsatisfied:
    ada_target_gcc_14