$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_bytes.git /var/lib/mock/f42-build-side-1-3581453-46829/root/chroot_tmpdir/scmroot/rust-serde_bytes
Cloning into '/var/lib/mock/f42-build-side-1-3581453-46829/root/chroot_tmpdir/scmroot/rust-serde_bytes'...
$ git fetch origin 75916ab053b7992af35528543d0bddca093a2c20:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_bytes
 * [new ref]         75916ab053b7992af35528543d0bddca093a2c20 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 75916ab Update to version 0.11.17; Fixes RHBZ#2350999