On legacy/trac#24761, Sebastian says that we require Rust ~~1.14~~, but I can't see that documented anywhere. We should document it: * in the release notes * in the wiki: https://trac.torproject.org/projects/tor/wiki/RustInTor And point to it from: * https://gitweb.torproject.org/tor.git/tree/doc/HACKING/GettingStartedRust.md And document the nightly/feature thing in our coding standards: * https://gitweb.torproject.org/tor.git/tree/doc/HACKING/CodingStandardsRust.md