Description
A crater run was performed for Rust 1.38 and the digest of regressions is available in #63628 (comment).
The problem is that all regressions starting from "cannot use state because it was mutably borrowed" and below weren't analyzed.
It is too late to fix 1.38 now because it was released several weeks ago, but it's still useful to know what we regressed (there are >100 non-root regressions), some of those errors can be caused by legitimate bugs.
Triage is required mostly from people responsible for the rustc's middle-end (type checking and below).
cc @rust-lang/compiler