$ git clone -n https://src.fedoraproject.org/rpms/gentoo.git /var/lib/mock/f39-build-1462561-33345/root/chroot_tmpdir/scmroot/gentoo
Cloning into '/var/lib/mock/f39-build-1462561-33345/root/chroot_tmpdir/scmroot/gentoo'...
$ git fetch origin 7ee5edf8ff677df268859047fbe6f40428481bed:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gentoo
 * [new ref]         7ee5edf8ff677df268859047fbe6f40428481bed -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7ee5edf Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild