Hello, `net-vpn/i2p` currently adds a "i2p" user and group with a random uid/gid; it needs to run a daemon. I'm the proxy-maint for it so I created acct-{user,group}/i2p and assigned 493:493 which are free according to https://api.gentoo.org/uid-gid.txt
If that's good for you, the PR waiting validation is there https://github.com/gentoo/gentoo/pull/12785 Thanks. -- Valérian Rousset