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

Calculating dependencies ... done!
Dependency resolution took 0.99 s (backtrack: 0/20).

[ebuild   R    ] app-arch/zstd-1.5.7-r1:0/1::gentoo  USE="lzma zlib -lz4 -static-libs -test -verify-sig" 2378 KiB

Total: 1 package (1 reinstall), Size of downloads: 2378 KiB