$ git clone -n https://src.fedoraproject.org/rpms/rust-libsystemd.git /var/lib/mock/f40-build-2073147-49350/root/chroot_tmpdir/scmroot/rust-libsystemd
Cloning into '/var/lib/mock/f40-build-2073147-49350/root/chroot_tmpdir/scmroot/rust-libsystemd'...
$ git fetch origin 19c08c0c07c3cb65a6de67c03785dad4d3e68475:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-libsystemd
 * [new ref]         19c08c0c07c3cb65a6de67c03785dad4d3e68475 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 19c08c0 Update to version 0.7.0; Fixes RHBZ#1966652