$ git clone -n https://src.fedoraproject.org/rpms/rust-ipnetwork.git /var/lib/mock/f39-build-1521846-35863/root/chroot_tmpdir/scmroot/rust-ipnetwork
Cloning into '/var/lib/mock/f39-build-1521846-35863/root/chroot_tmpdir/scmroot/rust-ipnetwork'...
$ git fetch origin b93568e89ec7d65d940be880750fb38ac99f1e52:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-ipnetwork
 * [new ref]         b93568e89ec7d65d940be880750fb38ac99f1e52 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b93568e Update to version 0.20.0; Fixes RHBZ#2074770