$ git clone -n https://src.fedoraproject.org/rpms/rust-bytes.git /var/lib/mock/f41-build-side-1-2923660-34982/root/chroot_tmpdir/scmroot/rust-bytes
Cloning into '/var/lib/mock/f41-build-side-1-2923660-34982/root/chroot_tmpdir/scmroot/rust-bytes'...
$ git fetch origin 7a262c13f0b5fcb1c101022b296d2e88cdcd9ca2:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-bytes
 * [new ref]         7a262c13f0b5fcb1c101022b296d2e88cdcd9ca2 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7a262c1 Update to version 1.7.2; Fixes RHBZ#2313166