$ git clone -n https://src.fedoraproject.org/rpms/rust-struct-patch-derive.git /var/lib/mock/f45-build-45224-821/root/chroot_tmpdir/scmroot/rust-struct-patch-derive
Cloning into '/var/lib/mock/f45-build-45224-821/root/chroot_tmpdir/scmroot/rust-struct-patch-derive'...
$ git fetch origin d21542af9f1460064261c03ea608fbfaf31e963b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-struct-patch-derive
 * [new ref]         d21542af9f1460064261c03ea608fbfaf31e963b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d21542a Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild