$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_with.git /var/lib/mock/f45-build-44861-818/root/chroot_tmpdir/scmroot/rust-serde_with
Cloning into '/var/lib/mock/f45-build-44861-818/root/chroot_tmpdir/scmroot/rust-serde_with'...
$ git fetch origin 8de361f84273d6879417f9d588aee7dc28dcafef:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_with
 * [new ref]         8de361f84273d6879417f9d588aee7dc28dcafef -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8de361f Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild