$ git clone -n https://src.fedoraproject.org/rpms/rust-tokio-util.git /var/lib/mock/f45-build-45533-823/root/chroot_tmpdir/scmroot/rust-tokio-util
Cloning into '/var/lib/mock/f45-build-45533-823/root/chroot_tmpdir/scmroot/rust-tokio-util'...
$ git fetch origin b225b4d0cc3364eaf226c9b90862b70a37a578b1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-tokio-util
 * [new ref]         b225b4d0cc3364eaf226c9b90862b70a37a578b1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b225b4d Update to version 0.7.19; Fixes RHBZ#2503359