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

Calculating dependencies ...

!!! Problem resolving dependencies for =media-sound/csound-6.17.0-r1
 done!
Dependency resolution took 0.84 s (backtrack: 0/20).


!!! The ebuild selected to satisfy "=media-sound/csound-6.17.0-r1" has unmet requirements.
- media-sound/csound-6.17.0-r1::gentoo USE="alsa cxx nls threads utils -beats -curl -debug -doc -double-precision -dssi -examples -jack -java -lua -osc -portaudio -portmidi -pulseaudio -samples -static-libs -test -vim-syntax" LUA_SINGLE_TARGET="lua5-1 -luajit" PYTHON_SINGLE_TARGET="-python3_12 -python3_13"

  The following REQUIRED_USE flag constraints are unsatisfied:
    exactly-one-of ( python_single_target_python3_12 python_single_target_python3_13 )

  The above constraints are a subset of the following complete expression:
    exactly-one-of ( python_single_target_python3_12 python_single_target_python3_13 ) alsa? ( threads ) java? ( cxx ) lua? ( exactly-one-of ( lua_single_target_luajit lua_single_target_lua5-1 ) cxx )