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

Calculating dependencies ...

!!! Problem resolving dependencies for =www-misc/buku-4.9
 done!
Dependency resolution took 0.83 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=www-misc/buku-4.9" has unmet requirements.
- www-misc/buku-4.9::gentoo USE="-test" PYTHON_TARGETS="-python3_12 -python3_13"

  The following REQUIRED_USE flag constraints are unsatisfied:
    any-of ( python_targets_python3_12 python_targets_python3_13 )