rust-toolchain.toml

# The counterpart to .node-version. A compiler change is a codegen change, and
# codegen determines the bytes of the committed engine.wasm, so this pin is a
# correctness control rather than a convenience.
#
# Measured 2026-08-16 (#218): this pin produces a BYTE-IDENTICAL module on
# aarch64-apple-darwin and x86_64-unknown-linux-gnu. That result belongs to the
# pin, so bumping this file means re-running the #218 probe, not assuming the
# property carries over.
#
# RE-RUN AT 1.98.0 ON 2026-08-25, and note that the gate itself is the probe:
# `scripts/verify-rust.sh` rebuilds and `cmp`s against the committed module, and
# the `rust` CI job runs it on ubuntu x86_64 while the artifact is built here on
# macOS aarch64. So a green `rust` check on a toolchain-bump PR IS the
# cross-host byte-identity result - there is nothing extra to run by hand.
#
# 1.97.1 -> 1.98.0 moved the module 178,593 -> 178,531 bytes. A compiler change
# is a codegen change, so that was expected; what matters is that no RESULT
# moved, and tier 3 pins that independently by comparing WASM renders against
# the TypeScript byte for byte.
#
# Note rustup treats `1.98.0-<host>` and `stable-<host>` as separate installs
# even at the same version, so the first cargo command after a fresh clone
# downloads a toolchain even though `stable` is already 1.98.0.
[toolchain]
channel = "1.98.0"
components = ["rustfmt", "clippy"]
targets = ["wasm32-unknown-unknown"]
profile = "minimal"