Renaming the WASI target in Rust 1.71.0

posts/2023-04-27-wasi-target-rename-1.71.0.md

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+---
+layout: post
+title: "Renaming the WASI target in Rust 1.71.0"
+author: Yoshua Wuyts
+release: false
+---
+
+In Rust 1.71 the existing `wasm32-wasi` target will be renamed to
+`wasm32-wasi-preview1`. This matches the naming used in the [WASI Preview
+Framework][wpf] and more accurately captures the evolving nature of the WASI
+targets. By making this change we also prepare Rust to re-adopt the
+`wasm32-wasi` target name for the eventual stable WASI 1.0 release.
+
+[wpf]: https://github.com/WebAssembly/meetings/blob/main/wasi/2023/presentations/2023-02-09-gohman-wasi-roadmap.pdf
+
+Work on adding a WASI Preview 2 target to the compiler is currently underway,
+but is not yet complete. We expect this to land in a future release of Rust. The
+target triple for this target will be `wasm32-wasi-preview2`.
+
+## Migrating Targets
+
+To upgrade to the new WASI target on Rust 1.71 nightly you can run the
+following commands using [rustup](https://rustup.rs):
+
+```bash
+$ rustup +nightly target remove wasm32-wasi
+$ rustup upgrade nightly
+$ rustup +nightly target add wasm32-wasi-preview1
+```
+
+Once beta and stable builds are available (expected in ~6 and ~12 weeks
+respectively) you should be able to replace the word `nightly` with either
+`beta` or `stable` in the instructions.