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

Calculating dependencies ... done!
Dependency resolution took 0.96 s (backtrack: 0/20).

[ebuild   R    ] dev-libs/libfmt-12.1.0:0/12.1.0::gentoo  USE="-test" 695 KiB

Total: 1 package (1 reinstall), Size of downloads: 695 KiB