$ git clone -n https://src.fedoraproject.org/rpms/rust-pep508_rs.git /var/lib/mock/f39-build-1544001-36605/root/chroot_tmpdir/scmroot/rust-pep508_rs
Cloning into '/var/lib/mock/f39-build-1544001-36605/root/chroot_tmpdir/scmroot/rust-pep508_rs'...
$ git fetch origin 5c8eecb067f8f2bb3d200355fe9f3e6e9e73b82a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pep508_rs
 * [new ref]         5c8eecb067f8f2bb3d200355fe9f3e6e9e73b82a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 5c8eecb Update to version 0.2.3; Fixes RHBZ#2241059