• perf.rust-lang.org is switching to a new benchmarking server so all of the old data is being removed to avoid skewed comparisons.

  • The constant propagation MIR optimization pass is on by default which provides some improvements to debug and release compile times.

  • @pnkfelix wrote a blog post about minimizing rustc bugs.

Backport nominations

  • “Do not ICE on trait aliases with missing obligations” #66392

    • Accepted for stable backport
  • “Fix ICE when trying to suggest Type<> instead of Type()” #66390

    • Accepted for stable backport
  • “Do not ICE on recovery from unmet associated type bound obligation” #66388

    • Accepted for stable backport
  • “find_deprecation: deprecation attr may be ill-formed meta.” #66381

    • Accepted for stable backport
  • “parser: don’t use unreachable!() in fn unexpected.” #66361

    • Accepted for stable backport

Working group sync


  • @Alexander Regueiro is very close to landing support for trait object upcasts.

  • Chalk is being refactored with the goal of revamping how the rustc integration works so they share a lot more code.

  • @Jack Huey has been fixing the handling of coinduction logic and generally refactoring the chalk engine.

  • Work has been proceeding to fix a soundess hole related to dyn Trait (#57893)