2019-11-21

Announcements

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.

“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

@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)