$ git clone -n https://src.fedoraproject.org/rpms/rust-pep508_rs.git /var/lib/mock/f42-build-side-1-3581428-46829/root/chroot_tmpdir/scmroot/rust-pep508_rs
Cloning into '/var/lib/mock/f42-build-side-1-3581428-46829/root/chroot_tmpdir/scmroot/rust-pep508_rs'...
$ git fetch origin c52cc83b52b8a23751b85d41724a741f5da56e00:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pep508_rs
 * [new ref]         c52cc83b52b8a23751b85d41724a741f5da56e00 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c52cc83 Update to version 0.9.2; Fixes RHBZ#2321402