once toolchain
Inspect the project toolchain contract
Synopsis
text
once toolchain [OPTIONS] <SUBCOMMAND>Description
Reports the toolchains a project pins (Rust, Swift, mise) and the resolved versions Once will use when running actions from script adapters or graph target kinds. Once downloads and verifies its own release-pinned mise executable when it is first needed, so the command does not depend on a developer-installed mise. Pair with once query schema when debugging "why did the cache miss?" questions where the toolchain identity is suspect.
Options
| Flag | Value | Default | Description |
|---|---|---|---|
-C, --directory | <DIR> | Project root. Defaults to the current directory; the cache lives under <project>/.once/. Mirrors make -C | |
--format | <FORMAT> | human | Output format for Once's structured data (cache stats, run/exec trailers). Defaults to a human-readable rendering; pass json or toon to get machine-parseable output for scripting and for agent consumers |
-v, --verbose | (flag) | 0 | Increase log verbosity. Repeat for more (-v: info, -vv: debug, -vvv: trace). Overridden by RUST_LOG |
-q, --quiet | (flag) | false | Suppress human-mode success and progress trailers. Errors and the structured envelope of --format json/toon still print. Mirrors the -q flag of common build tools |
--list | (flag) | false | Print the command surface at the current command depth |