$ git clone -n https://src.fedoraproject.org/rpms/rust-pem.git /var/lib/mock/f40-build-2653244-66900/root/chroot_tmpdir/scmroot/rust-pem
Cloning into '/var/lib/mock/f40-build-2653244-66900/root/chroot_tmpdir/scmroot/rust-pem'...
$ git fetch origin 6bacd9ea0e11bb0ac9791799ee835d0c34c8afa9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pem
 * [new ref]         6bacd9ea0e11bb0ac9791799ee835d0c34c8afa9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6bacd9e Update to version 3.0.3; Fixes RHBZ#2225570