Enum RunCommandError 

#[non_exhaustive]
pub enum RunCommandError {
    #[non_exhaustive]
    IncompleteRun {
        invocation: Box<Invocation>,
        source: Error,
    },
    #[non_exhaustive]
    UnstartableCommand {
        invocation: Box<Invocation>,
        source: Error,
    },
}

The error returned when a command does not run

The variants separate what happened to the command. A command that never started needs a program that exists, a working directory that exists, and the rights to start a program. A run that started and did not finish means that the operating system stopped the crate from collecting the result, which a caller reports and can try again.

A command that ran and ended without success is no failure of the run. The result then carries the status, and the caller decides what it means.

The invocation travels in a box. A result carries its error by value, so the size of the error reaches every function that returns one. The box keeps the error small, and a caller that wraps it in an error of its own needs no box for it.

A later release can add variants, and it can add fields to a variant. Match with a wildcard arm, and bind the fields of a variant with ...

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.

#[non_exhaustive]

IncompleteRun

The command started and the run did not finish

The program ran, and reading one of its streams or waiting for its end failed. Nothing of the run survives such a failure, so the crate reports it instead of a result with holes in it. The command itself can still have done its work.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

invocation: Box<Invocation>

The command that did not finish

source: Error

The cause of the failure

#[non_exhaustive]

UnstartableCommand

The command did not start

No program answers to the name, the working directory does not exist, or the operating system refused to start the program. Nothing ran, so there is no status and no output to report.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

invocation: Box<Invocation>

The command that did not start

source: Error

The cause of the failure

Trait Implementations

impl Debug for RunCommandError

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

Formats the value using the given formatter.

impl Display for RunCommandError

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

Formats the value using the given formatter.

impl Error for RunCommandError

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.