$ git clone -n https://src.fedoraproject.org/rpms/rust-serde_plain.git /var/lib/mock/f45-build-44844-818/root/chroot_tmpdir/scmroot/rust-serde_plain
Cloning into '/var/lib/mock/f45-build-44844-818/root/chroot_tmpdir/scmroot/rust-serde_plain'...
$ git fetch origin b1488e73cabf468eea2e37fbc0d623c634b268f8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-serde_plain
 * [new ref]         b1488e73cabf468eea2e37fbc0d623c634b268f8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b1488e7 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild