Enum PluginHostError 

pub enum PluginHostError {
    Engine(Error),
    EpochTicker(Error),
    Linker(Error),
    Cache(Error),
    Compile(Error),
    Instantiate(Error),
    GrammarSpec(String),
    Trap {
        func: &'static str,
        kind: TrapKind,
        source: Error,
    },
    PluginGone {
        func: &'static str,
    },
    Quarantined {
        func: &'static str,
    },
    Boundary(String),
}

Typed error surface for the plugin host. No host path panics — every failure mode is a value here (the four-artefact graceful-error clause). anyhow::Error is wasmtime’s error type; each variant carries it as #[source].

Variants

Engine(Error)

The wasmtime engine could not be built from the host config.

EpochTicker(Error)

The epoch-ticker background thread could not be spawned (the OS refused a thread). Surfaced rather than panicked — no host-construction path panics (the “every failure mode is a value” invariant).

Linker(Error)

The component linker could not be populated with the WASI host functions (PH7.2). A host-setup failure, surfaced rather than panicked.

Cache(Error)

The on-disk module cache could not be initialised (bad directory, I/O error). A caching failure must never fail the host — callers may fall back to an uncached host — so this is surfaced, never panicked.

Compile(Error)

Component bytes were malformed or failed AOT compilation.

Instantiate(Error)

The component compiled but could not be instantiated (a missing import, or fuel exhausted during the start function).

GrammarSpec(String)

A grammar plugin declared a malformed contribution spec (PH7.7c): an arg-spec / latency-class / surface-form that could not cross the boundary. Fails registration loudly (the spec is structurally wrong), unlike a runtime apply failure, which degrades gracefully to a no-op.

Trap

A lifecycle export trapped. Fuel/epoch exhaustion and genuine wasm traps all land here as a value — the call is a no-op with a typed error and the host stays live.

Fields

func: &'static str

The export that trapped ("activate" / "deactivate").

kind: TrapKind

What caused the trap (fuel / epoch / other).

source: Error

The underlying wasmtime trap.

PluginGone

A guest call was routed to a per-plugin actor task (picker_task) whose channel is closed — the task has ended and dropped its Store (teardown, or a fatal error unwound the loop). The call is a no-op with a typed error; the caller stays live. This is the bridge’s graceful surface for “the plugin is gone”, distinct from Trap (the plugin ran but its call failed).

Fields

func: &'static str

The export the caller was trying to reach ("spec" / "init" / "accept").

Quarantined

The plugin instance is quarantined (PH7.12): a prior lifecycle / callback call trapped, tripping crash-quarantine, so this call short-circuits before re-entering the dead Store. Distinct from Trap (the plugin ran and its call failed) and PluginGone (the actor’s channel is closed): the actor is still alive, but the instance is dead-until-reinstantiation. The PluginCrashed event already fired on the first trap; this variant is the quiet no-op every subsequent call returns until a reload (PH7.12b) mints a fresh instance.

Fields

func: &'static str

The export the caller was trying to reach.

Boundary(String)

A value crossing the picker boundary could not be converted between its WIT mirror and the native type — a malformed record the guest returned (e.g. a non-UTF-8 path, §4.4), or a native value with no WIT representation. Carries the boundary layer’s message. Never lossy: a conversion that cannot be represented is this typed error, not a silent drop.

Trait Implementations

impl Debug for PluginHostError

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

Formats the value using the given formatter.

impl Display for PluginHostError

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

Formats the value using the given formatter.

impl Error for PluginHostError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.