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

Calculating dependencies ... done!
Dependency resolution took 1.03 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/libcbor-0.14.0:0/0.14::gentoo  USE="-doc -test" 310 KiB
[ebuild  N     ] acct-group/plugdev-0-r3::gentoo  0 KiB
[ebuild  N     ] dev-libs/libfido2-1.17.0:0/1::gentoo  USE="-hidapi -nfc -smartcard -static-libs -test" 694 KiB

Total: 3 packages (3 new), Size of downloads: 1004 KiB