Enum SchemaError 

#[non_exhaustive]
pub enum SchemaError {
    Io {
        path: PathBuf,
        source: Error,
    },
    Parse {
        path: PathBuf,
        message: String,
    },
    UnsupportedSchemaVersion {
        path: PathBuf,
        label: String,
        version: u32,
    },
    UnknownNodeKind {
        path: PathBuf,
        label: String,
        kind: String,
    },
    EmptyEnumValues {
        path: PathBuf,
        label: String,
        param: String,
    },
    DuplicateEnumValue {
        path: PathBuf,
        label: String,
        param: String,
        value: String,
    },
    EmptyEnumValueName {
        path: PathBuf,
        label: String,
        param: String,
    },
    InvalidVerbatimLabel {
        path: PathBuf,
        label: String,
        reason: String,
    },
    WasmTransportDeferred {
        path: PathBuf,
        label: String,
    },
    EmptySubprocessCommand {
        path: PathBuf,
        label: String,
    },
    UnsupportedTransport {
        path: PathBuf,
        label: String,
        transport: String,
    },
}

One schema file failed to load. Variants distinguish post-deserialise validation failures by class so callers can pattern-match on the cause. The deserialise step is one variant — Parse — because serde_yaml reports missing required fields, wrong-typed fields, and unknown fields (rejected by deny_unknown_fields) all through the same error path with line/column attribution baked into the message.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Io

Reading the file (or, for load_dir, listing the directory or one of its entries) failed at the OS level.

Fields

path: PathBuf

source: Error

Parse

The YAML body did not deserialise into a Schema. The message is whatever serde_yaml produced — which carries line/column information when attribution is possible. Reasons covered by this single variant: missing required field, wrong-typed field, unknown field rejected by deny_unknown_fields, malformed YAML.

Fields

path: PathBuf

message: String

UnsupportedSchemaVersion

schema_version is set to a value the loader doesn’t support. Currently only 1 is recognised; future versions land with dedicated migration paths, not a permissive accept.

Fields

path: PathBuf

label: String

version: u32

UnknownNodeKind

attaches_to referenced a node kind outside the closed set defined by HostNodeKind::ALL. The Display impl emits the current allowed list verbatim so the error stays in sync if new kinds are added.

Fields

path: PathBuf

label: String

kind: String

EmptyEnumValues

A param declared type: enum but its values list is empty.

Fields

path: PathBuf

label: String

param: String

DuplicateEnumValue

Two EnumValue entries on the same param share a name.

Fields

path: PathBuf

label: String

param: String

value: String

EmptyEnumValueName

An EnumValue was declared with an empty name. The empty string isn’t a useful identifier and almost always indicates a schema typo (- name: with no value).

Fields

path: PathBuf

label: String

param: String

InvalidVerbatimLabel

verbatim_label: true was set on a label that can’t legally appear as a verbatim block closing — typically because it contains whitespace or the verbatim-marker sequence ::.

Fields

path: PathBuf

label: String

reason: String

WasmTransportDeferred

handler.transport: wasm is reserved for a future release. The loader rejects it with a clear deferral message rather than the generic “unknown variant” error so users get an actionable hint.

Fields

path: PathBuf

label: String

EmptySubprocessCommand

handler.transport: subprocess declared without a non-empty command array — the subprocess transport has nothing to spawn.

Fields

path: PathBuf

label: String

UnsupportedTransport

handler.transport is a value the loader doesn’t understand. HandlerTransport is #[non_exhaustive] upstream; reaching this branch means a future variant slipped past serde without being taught to the validator. Surfacing it as an error rather than a silent accept keeps lockstep with lex-extension.

Fields

path: PathBuf

label: String

transport: String

Trait Implementations

impl Debug for SchemaError

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

Formats the value using the given formatter.

impl Display for SchemaError

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

Formats the value using the given formatter.

impl Error for SchemaError

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.