Enum FlowError 

pub enum FlowError {
    AlreadyExists(String),
    NotFound(String),
    InvalidArgument(String),
    ScopeStackEmpty,
    GuardrailRejected(String),
    Internal(String),
}

The error type for all NeMo Flow runtime operations.

Each variant represents a distinct failure mode that callers can match on to determine the appropriate recovery strategy.

Variants

AlreadyExists(String)

A resource with the given name is already registered.

Returned when attempting to register a guardrail, intercept, or subscriber with a name that is already in use. Deregister the existing entry first, or choose a different name.

NotFound(String)

The requested resource was not found.

Returned when attempting to remove a scope handle by UUID that does not exist in the scope stack, or when looking up a non-existent entity.

InvalidArgument(String)

A function argument was invalid for the requested operation.

Returned when a provided value is well-formed but violates an API precondition, such as attempting to pop a scope that is not currently at the top of the stack.

ScopeStackEmpty

The scope stack is empty.

This should not occur under normal operation because the root scope is always present and cannot be removed.

GuardrailRejected(String)

A conditional execution guardrail rejected the operation.

The contained string is the rejection reason provided by the guardrail. This is returned during tool_call_execute or llm_call_execute when a conditional guardrail returns Some(reason).

Internal(String)

An internal runtime error (e.g., lock poisoning).

Trait Implementations

impl Debug for FlowError

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

Formats the value using the given formatter.

impl Display for FlowError

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

Formats the value using the given formatter.

impl Error for FlowError

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.

impl From<FlowError> for AtofExporterError

fn from(source: FlowError) -> Self

Converts to this type from the input type.

impl From<FlowError> for OpenInferenceError

fn from(source: FlowError) -> Self

Converts to this type from the input type.

impl From<FlowError> for OpenTelemetryError

fn from(source: FlowError) -> Self

Converts to this type from the input type.