Enum RunError 

#[non_exhaustive]
pub enum RunError {
    Spawn {
        program: String,
        source: Error,
    },
    NonZeroExit {
        program: String,
        args: Vec<String>,
        status: ExitStatus,
        stdout: Vec<u8>,
        stderr: String,
    },
    Timeout {
        program: String,
        args: Vec<String>,
        elapsed: Duration,
        stdout: Vec<u8>,
        stderr: String,
    },
}

Error type for subprocess execution.

Distinguishes between:

• Spawn: infrastructure failure (binary missing, fork failed, etc.)
• NonZeroExit: the command ran and reported failure via exit code
• Timeout: the command was killed after exceeding its timeout

Marked #[non_exhaustive] so future variants can be added without breaking callers. Match with a wildcard arm to handle unknown variants defensively.

let repo = Path::new("/repo");
let maybe_bytes = match run_git(repo, &["show", "maybe-missing-ref"]) {
    Ok(output) => Some(output.stdout),
    Err(RunError::NonZeroExit { .. }) => None,   // ref not found
    Err(e) => return Err(e.into()),              // real failure bubbles up
};

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.

Spawn

Failed to spawn the child process. The binary may be missing, the working directory may not exist, or the OS may have refused the fork.

Fields

program: String

source: Error

NonZeroExit

The child process ran but exited non-zero. For captured commands, stdout and stderr contain what the process wrote before exiting. For inherited commands (crate::run_cmd_inherited), they are empty.

Fields

program: String

args: Vec<String>

status: ExitStatus

stdout: Vec<u8>

stderr: String

Timeout

The child process was killed after exceeding the caller’s timeout.

Any output written to stdout/stderr before the kill signal is included when available. The elapsed field records how long the process ran.

Fields

program: String

args: Vec<String>

elapsed: Duration

stdout: Vec<u8>

stderr: String

Implementations

impl RunError

pub fn program(&self) -> &str

The program name that failed (e.g., "git", "jj").

pub fn stderr(&self) -> Option<&str>

The captured stderr, if any. None for spawn failures.

pub fn exit_status(&self) -> Option<ExitStatus>

The exit status, if the process actually ran to completion. None for spawn failures and timeouts.

pub fn is_non_zero_exit(&self) -> bool

Whether this error represents a non-zero exit (the command ran and reported failure).

pub fn is_spawn_failure(&self) -> bool

Whether this error represents a spawn failure (couldn’t start the process).

pub fn is_timeout(&self) -> bool

Whether this error represents a timeout (process killed after exceeding its time budget).

Trait Implementations

impl Debug for RunError

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

Formats the value using the given formatter.

impl Display for RunError

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

Formats the value using the given formatter.

impl Error for RunError

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.