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

Calculating dependencies ... done!
Dependency resolution took 1.07 s (backtrack: 0/20).

[ebuild  N     ] acct-group/tss-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/tss-0-r3::gentoo  0 KiB
[ebuild  N     ] app-crypt/tpm2-tss-4.2.0:0/4::gentoo  USE="fapi openssl policy -doc -mbedtls -static-libs -test" 1977 KiB

Total: 3 packages (3 new), Size of downloads: 1977 KiB