Struct RunContext 

pub struct RunContext<'a, F, S, O>
where
    F: WritableFilesystem,
    S: ProcessSpawner,
    O: RunObserver,
{
    pub fs: &'a F,
    pub cache: &'a Cache<F>,
    pub spawner: &'a S,
    pub observer: &'a O,
    pub workspace: &'a Workspace,
    pub graph: &'a TaskGraph,
    pub host_env: &'a BTreeMap<EnvVarName, String>,
    pub algo: HashAlgo,
    pub cancel: &'a CancellationToken,
}

Borrowed bundle of long-lived state that every run_task invocation in a given haz run shares.

The split between this context and the per-task arguments matches a scheduler’s natural shape: one RunContext covers the entire scheduling loop, while task, predecessor_streams, and created_at_unix change between individual run_task calls.

Fields

fs: &'a F

Filesystem the executor reads inputs / outputs / cache state through.

cache: &'a Cache<F>

Cache handle (lookup, restore, store).

spawner: &'a S

Process spawner (a test-double mock under cfg(test), crate::std_impl::StdProcessSpawner in production).

observer: &'a O

Observer that receives lifecycle events and captured streams.

workspace: &'a Workspace

Validated workspace state.

graph: &'a TaskGraph

Validated dependency graph.

host_env: &'a BTreeMap<EnvVarName, String>

Host-environment snapshot. Names not present here are treated as absent per CACHE-008.

algo: HashAlgo

Active hash algorithm for cache-key derivation, input / output content hashing, and captured-stream hashing.

cancel: &'a CancellationToken

Cancellation signal for the run (EXEC-012 triggers). The scheduler and per-task spawn-step futures observe this token: when it fires, the scheduler stops admitting new tasks and in-flight futures send SIGTERM to their children. The token is long-lived ambient state owned by the run’s caller (typically haz-cli installing an OS signal handler); tests pass a never-cancelled token.