Allow use of wasip3 0.3 for MSRV reasons (#824)

This allows a project dependeing on `getrandom` to use this to get an
Fully Rust-1.85-compatible Cargo.lock, while still allowing projects
with newer MSRV to use 0.4.

Author: briansmith

CHANGELOG.md

@@ -4,6 +4,13 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+- Restore MSRV to 1.85 for wasm32-wasip3 targets. [#824]
+
+[Unreleased]: https://github.com/rust-random/getrandom/compare/v0.4.2...master
+[#824]: https://github.com/rust-random/getrandom/pull/824
+
 ## [0.4.2] - 2026-03-03
 
 ### Changed

Cargo.toml

@@ -82,7 +82,8 @@ wasip2 = { version = "1", default-features = false }
 
 # wasi_p2_3
 [target.'cfg(all(target_arch = "wasm32", target_os = "wasi", target_env = "p3"))'.dependencies]
-wasip3 = "0.4"
+# TODO: remove 0.3 after MSRV bumped to 1.87+.
+wasip3 = ">=0.3, <=0.4"
 
 # wasm_js
 [target.'cfg(all(target_arch = "wasm32", any(target_os = "unknown", target_os = "none")))'.dependencies]

README.md

@@ -326,6 +326,13 @@ RUSTFLAGS="-Zsanitizer=memory" cargo test -Zbuild-std --target=x86_64-unknown-li
 
 This crate requires Rust 1.85 or later.
 
+The most reliable way to get an MSRV-respecting behavior is to set
+`CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS=fallback` when doing
+`cargo update -p getrandom`, like so:
+```sh
+CARGO_RESOLVER_INCOMPATIBLE_RUST_VERSIONS=fallback cargo update -p getrandom
+```
+
 ## License
 
 The `getrandom` library is distributed under either of