Main's order of 7 October 2026. The repo root carries rust-toolchain.toml (channel 1.99.0, targets x86_64-pc-windows-gnu and
x86_64-unknown-linux-gnu); rustup resolves the nearest file walking up from the crate, so the fork worktrees under vendor/ are
covered, and the fork's master carries its own copy (vendor/igneum-node 37f1206b). lib.sh bs_toolchain_check reads the pin
and refuses a build when the pin, the Mac's rustc as resolved in the crate dir, or the box's rustc differ (the message says
the three commands that align them); run-from-mac.sh passes the pin to provision.sh as RUST_TOOLCHAIN. The 1.99.0 toolchain
with both targets is installed on the Mac so no agent's build stalls on rustup's auto-install. Verified: the Mac resolves
1.99.0 in a fork worktree, the box runs 1.99.0, the check prints 'pinned 1.99.0 by rust-toolchain.toml'.
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
