Struct LoadOptions 

pub struct LoadOptions<'a> {
    pub artifacts: Option<&'a Path>,
    pub global_timeout: Option<Duration>,
}

What a load needs beyond the config file, for a caller that has more to say than load can carry.

A struct rather than two more parameters, for the reason lanekeep-cli’s CheckOptions gives: artifacts and the config path are both &Path, and adjacent parameters of one type are the shape that gets silently transposed at a call site.

Fields

artifacts: Option<&'a Path>

A project root under which compiled components may be cached, or None for a load with nowhere to write.

This is the difference between a component costing something per config load and costing nothing. With None, describe_components compiles every component from scratch to ask it what it is, throws the compilation away, and the engine compiles the same bytes again at prepare time. Measured on the release binary, one 26 KB Rust component added ~58 ms to a lanekeep rules that checks no files at all, and two added ~116 ms — against a §15 warm-run budget of 25 ms for the whole invocation. Config load runs per LSP request, per MCP tool call and per --watch iteration, so this is paid on every one of them.

Those figures are for a component of a few tens of kilobytes and do not generalize. The shared TypeScript built-ins are one 12.4 MiB artifact, and compiling it is about six seconds — a hundredfold, not a factor. docs/architecture.md §15 has the table. So the choice between Some and None is a question about seconds rather than milliseconds for any caller whose config names one of those four rules, which is why RuleTester::for_built_in would be unusable without a root and why lanekeep-testkit names one.

Given a root, both loads write and map artifacts under the same COMPONENT_CACHE_PATH, keyed on the specifier and the bytes — so the first run compiles once instead of twice and every later run maps what that run wrote. The two loaders agree because both build their wasmtime::Engine with WasmEngine::new; an artifact a different build wrote fails to deserialize and is discarded rather than trusted.

Named by the caller rather than inferred, because a rules root is the project root only by the CLI’s choice, and guessing would make loading a config write somewhere nobody asked for. lanekeep-testkit anchors a rules root at a temporary fixture directory and names that — which is the shape this field is for: the caller knows it owns the directory and removes it, and this function could not have known either.

global_timeout: Option<Duration>

Overrides timeouts.global from the config file, for a caller holding a more specific statement — --timeout, which a user typed on this run.

It has to arrive here rather than be applied to the returned Config, because config load is itself a phase that runs guest code. describe_components instantiates, configures and calls metadata on every component under a clock of its own, and that clock is built before this function returns. A caller that loaded first and assigned to Config::limits afterwards would leave that phase governed by the config file’s number while the message a breach prints tells the user to raise it with --timeout — advice that could not work. AGENTS.md records the original instance of exactly this shape.

Trait Implementations

impl<'a> Clone for LoadOptions<'a>

fn clone(&self) -> LoadOptions<'a>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<'a> Copy for LoadOptions<'a>

impl<'a> Debug for LoadOptions<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'a> Default for LoadOptions<'a>

fn default() -> LoadOptions<'a>

Returns the “default value” for a type.