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

Calculating dependencies ... done!
Dependency resolution took 1.59 s (backtrack: 0/20).

[ebuild     U  ] net-misc/curl-8.21.0-r1::gentoo [8.19.0::gentoo] USE="adns alt-svc ftp hsts http2 http3 httpsrr imap openssl pop3 psl quic smtp ssh ssl tftp websockets -brotli -debug (-ech) -gnutls -gopher -idn -kerberos -ldap -mbedtls -rustls -sasl-scram -static-libs -telnet -test -verify-sig -zstd (-rtmp%) (-samba%)" CURL_SSL="openssl -gnutls -mbedtls -rustls" 2823 KiB

Total: 1 package (1 upgrade), Size of downloads: 2823 KiB