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

Calculating dependencies ... done!
Dependency resolution took 1.04 s (backtrack: 0/20).


The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by media-gfx/blender-4.2.16::gentoo
# required by =media-gfx/blender-4.2.16 (argument)
>=media-libs/freetype-2.15.0 brotli

!!! The ebuild selected to satisfy "<media-libs/openimageio-3:=" has unmet requirements.
- media-libs/openimageio-2.5.19.1::gentoo USE="gif jpeg2k python tools truetype -dicom -doc -ffmpeg -fits -gui -opencv -openvdb -ptex -raw -test" CPU_FLAGS_X86="aes avx avx2 avx512f f16c sse2 sse3 sse4_1 sse4_2 ssse3" PYTHON_SINGLE_TARGET="-python3_12 -python3_13"

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

  The above constraints are a subset of the following complete expression:
    python? ( exactly-one-of ( python_single_target_python3_12 python_single_target_python3_13 ) ) gui? ( tools ) test? ( tools truetype )

(dependency required by "media-gfx/blender-4.2.16::gentoo" [ebuild])
(dependency required by "=media-gfx/blender-4.2.16" [argument])