$ git clone -n https://src.fedoraproject.org/rpms/rust-prost.git /var/lib/mock/f41-build-side-1-2902634-34658/root/chroot_tmpdir/scmroot/rust-prost
Cloning into '/var/lib/mock/f41-build-side-1-2902634-34658/root/chroot_tmpdir/scmroot/rust-prost'...
$ git fetch origin 71d18025a80896ec0cb39006221903ee5aa9cec7:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-prost
 * [new ref]         71d18025a80896ec0cb39006221903ee5aa9cec7 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 71d1802 Update to version 0.13.3; Fixes RHBZ#2313984