$ git clone -n https://src.fedoraproject.org/rpms/rust-pyo3_0.20.git /var/lib/mock/f41-build-side-1-2902642-34658/root/chroot_tmpdir/scmroot/rust-pyo3_0.20
Cloning into '/var/lib/mock/f41-build-side-1-2902642-34658/root/chroot_tmpdir/scmroot/rust-pyo3_0.20'...
$ git fetch origin 1a6c77d4dda5f3a583c0e1fe5b95d2ddbbc8c335:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pyo3_0.20
 * [new ref]         1a6c77d4dda5f3a583c0e1fe5b95d2ddbbc8c335 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1a6c77d Make unsafe subinterpreter support available via cfg flag