$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_bytes.git /var/lib/mock/f39-build-2195385-51521/root/chroot_tmpdir/scmroot/rust-serde_bytes
Cloning into '/var/lib/mock/f39-build-2195385-51521/root/chroot_tmpdir/scmroot/rust-serde_bytes'...
$ git fetch origin f3434c9da98dd62759829b3d2bc51fe27ecfa93c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_bytes
 * [new ref]         f3434c9da98dd62759829b3d2bc51fe27ecfa93c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at f3434c9 Update to version 0.11.14; Fixes RHBZ#2256497