Rust for Mac

Compatibility Notes

• If fully elided, lifetime bounds of trait object types may now resolve differently or even get rejected in very specific niche scenarios
• Error in more cases of ambiguous imports
• Switch the destructors implementation for thread locals on Windows to use Fiber Local Storage (FLS)
• Convert some cases of the ambiguous_glob_imports lint into a hard error
• Where-bounds of the form Type = Type and Type == Type are no longer syntactically allowed
• Ensure Send/Sync is not implemented for std::env::Vars{,Os}
• Fix that in some attributes, arguments were not properly rejected
• repr(transparent) is now more strict about which fields have "trivial" layout and hence can be ignored: repr(C) types, types with private fields, and #[non_exhaustive] types are no longer considered "trivial"
• Correctly check whether types have equal size in transmute() when some repr attributes are involved.
• More characters are escaped when printing strings and chars
• Implement fast path for derive(PartialOrd) when deriving Ord This can break crates in practice where a type's PartialOrd and Ord impls were inconsistent with each other.
• Add temporary scope to assert_eq and assert_ne
• Closed a hole in the pattern matching structural equality check, preventing cases where a match of a constant would be allowed, despite disagreeing with a manually written PartialEq implementation, when a derive(PartialEq) implementation for that type also exists.
• On Emscripten the WASM exception handling ABI is now unconditionally used The -Zemscripten-wasm-eh=false flag to switch back to JS exceptions has been removed.
• The UNSAFE_CODE lint is now consistently emitted for all unsafe attributes
• Solaris: remove File::lock implementation, it has the wrong semantics (return "unsupported" instead)
• Windows-gnu targets now specify baseline tools versions
• rustfmt now discovers module files that are defined in cfg_select! This may cause more code to be formatted which was previously ignored.

Full list of changes available here