Really? What do you think comes from Ruby? Rust mostly seems to be inspired by ML and C++.
Actually I just checked the "official" list and they only list the closure syntax which seems pretty minor:
A significant portion of the prominent community members come from Ruby so I guess there must be something …
Iterator style, chaining, traits, blocks all feel very rubyesque, and expression syntax as well, plus the cargo toolchain is very bundler-informed.