$ git clone -n https://src.fedoraproject.org/rpms/rust-peg0.5.git /var/lib/mock/f45-build-43767-805/root/chroot_tmpdir/scmroot/rust-peg0.5
Cloning into '/var/lib/mock/f45-build-43767-805/root/chroot_tmpdir/scmroot/rust-peg0.5'...
$ git fetch origin cb728018950e52223af2874dc0af23d1dd08b439:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-peg0.5
 * [new ref]         cb728018950e52223af2874dc0af23d1dd08b439 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cb72801 Regenerate with rust2rpm v28