Rust 1.93.1: Quick Fixes and Why You Should Update Now
The stable channel just got a tiny but welcome patch. Rust 1.93.1 rolls back three regressions that managed to slip into 1.93.0, so the compiler, rustfmt, and wasm builds behave like they used to. This article shows how to get the update with rustup and explains why the fixes actually matter.
How to upgrade with rustup
If rustup is already on the machine, a single command does the job: run rustup update stable. The tool will fetch the newest metadata, replace the old binaries, and leave the current toolchain pointer pointing at 1.93.1. After it finishes, typing rustc --version should print something like “rustc 1.93.1 (… )”. Verifying the version is useful because a stale shell session can sometimes keep an older path cached; opening a new terminal clears that up automatically.
What the patch actually fixes
The first regression involved treating a language keyword as a normal identifier, which caused the compiler to hit an internal error (ICE). The bug showed up most often when rustfmt tried to reformat code containing newly introduced keywords. One developer reported that after upgrading to 1.93.0 their CI pipeline started failing on a large Rust‑fmt run, with cryptic “internal compiler error” messages that made the logs unreadable. The fix restores the old behavior, letting rustfmt finish without blowing up.
The second change silences a false positive from Clippy’s panicking_unwrap lint. In code where an implicit dereference occurs on a field access, Clippy would incorrectly flag the line as potentially panicking. That warning generated noise in many projects that already handled unwraps safely. The update tells Clippy to ignore those cases, so developers can focus on real issues instead of chasing phantom bugs.
Finally, the wasm‑related dependency bump from 1.93.0 introduced a file descriptor leak on the wasm32-wasip2 target. The leak manifested as “too many open files” errors when running long‑lived wasm services in production. By reverting the dependency version, the leak disappears for the rustup component that ships the target. Downstream toolchains still need to audit their own dependencies, but at least the official release no longer adds the problem.
Should you bother?
If the workflow includes rustfmt or Clippy, the 1.93.1 patch feels mandatory; the ICE and false‑positive lint have been known to stall builds for hours. For wasm developers targeting wasm32-wasip2, the leak can turn a stable service into an intermittent nightmare, so rolling back is a no‑brainer. Users who are stuck on 1.93.0 purely because they haven’t run an update in months might still see the bugs; a quick rustup refresh clears them out without any risk.
For anyone who prefers hand‑rolling Rust from source or uses a third‑party package manager, the same version numbers apply—just make sure the build pulls 1.93.1 instead of the buggy 1.93.0. The official installer still points at the stable channel, so most folks won’t have to think about it.
That’s it—grab the update, confirm the version, and enjoy a compiler that actually compiles.
Announcing Rust 1.93.1
Empowering everyone to build reliable and efficient software.
