$ git clone -n https://src.fedoraproject.org/rpms/rust-pyo3_0.19.git /var/lib/mock/f40-build-2718763-72972/root/chroot_tmpdir/scmroot/rust-pyo3_0.19
Cloning into '/var/lib/mock/f40-build-2718763-72972/root/chroot_tmpdir/scmroot/rust-pyo3_0.19'...
$ git fetch origin cad4bab9ee0e04ccdbe7b869e09e2ad4906f1041:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pyo3_0.19
 * [new ref]         cad4bab9ee0e04ccdbe7b869e09e2ad4906f1041 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cad4bab Drop deny(warnings) from doctests to fix building with recent Rust