$ git clone -n https://src.fedoraproject.org/rpms/rubygem-mime-types.git /var/lib/mock/f39-build-1499367-34744/root/chroot_tmpdir/scmroot/rubygem-mime-types
Cloning into '/var/lib/mock/f39-build-1499367-34744/root/chroot_tmpdir/scmroot/rubygem-mime-types'...
$ git fetch origin c59509b7e36dcdd067618f255a66c7e5cb1e168f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-mime-types
 * [new ref]         c59509b7e36dcdd067618f255a66c7e5cb1e168f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c59509b Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild