$ git clone -n https://src.fedoraproject.org/rpms/rust-pyo3-macros-backend.git /var/lib/mock/f39-build-1467645-33730/root/chroot_tmpdir/scmroot/rust-pyo3-macros-backend
Cloning into '/var/lib/mock/f39-build-1467645-33730/root/chroot_tmpdir/scmroot/rust-pyo3-macros-backend'...
$ git fetch origin 423d85a162c12cc33e17c4438ad34e836a1718a4:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-pyo3-macros-backend
 * [new ref]         423d85a162c12cc33e17c4438ad34e836a1718a4 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 423d85a Update to version 0.19.2; Fixes RHBZ#2228012