With -emit=dep-info=..., the -Zbinary-dep-depinfo option (though experimental it be) has proven to be extremely useful. We've been using this locally to quickly determine the set of files needed to upload (for remote building), while offloading the real work of linking and code-gen to remote execution. This has been effective at capturing all of the transitive rust crate dependencies needed.
This request is to make -Zbinary-dep-depinfo a permanently supported feature, graduate it from experimental. (Of course, the name of the flag may change.) Alternatively, provide the equivalent information about files needed for remote building some other way.