Enum Error 

#[non_exhaustive]
pub enum Error {
    Spawn {
        program: String,
        source: Error,
    },
    Exit {
        program: String,
        code: i32,
        stdout: String,
        stderr: String,
    },
    Timeout {
        program: String,
        timeout: Duration,
    },
    Parse {
        program: String,
        message: String,
    },
    Io(Error),
}

Errors produced when launching or running a child process.

Spawn failures, a non-zero exit (Exit), timeouts, and IO errors fold into one structured enum, so callers can pattern-match on the failure mode instead of parsing strings.

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

The child process could not be started (binary not found, permission denied, …).

Fields

program: String

The program we tried to launch.

source: Error

The underlying OS error.

Exit

The process ran to completion but exited with a non-zero status.

Produced by the ensure_success helpers; the raw exit code is otherwise reported without erroring (a non-zero exit is not inherently a failure).

Both captured streams are carried (each truncated to 4 KiB): git/jj write decisive diagnostics to stdout on failure (CONFLICT (content): …, nothing to commit, working tree clean), so a caller building a user-facing message wants stdout as a fallback when stderr is empty — see diagnostic.

Fields

program: String

The program that exited non-zero.

code: i32

The raw process exit code.

stdout: String

Captured standard output (truncated). Not shown in the Display message; kept for callers that need a stdout-borne failure message. For the raw-bytes helper (output_bytes) this is a lossy UTF-8 decode of stdout — the exact bytes remain on the originating ProcessResult.

stderr: String

Captured standard error (truncated). Not shown in the Display message to avoid log poisoning; this field holds what was kept.

Timeout

The process exceeded its configured timeout and was killed.

Fields

program: String

The program that timed out.

timeout: Duration

The deadline that elapsed.

Parse

The process succeeded but its output could not be parsed into the expected shape (e.g. malformed --json). Produced by the fallible-parse helpers on CliClient.

Fields

program: String

The program whose output failed to parse.

message: String

What went wrong.

Io(Error)

An IO error occurred while driving the process (reading a pipe, writing stdin, waiting for exit).

Implementations

impl Error

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

The best human-facing message for a failed run: captured standard error if it carries text, otherwise the captured standard output (where git puts CONFLICT … and git commit puts nothing to commit). Returns None when there is no captured output to show — a silent Exit (both streams blank) or any non-Exit variant (Spawn, Timeout, Parse, Io) — so a caller can fall back to the Display message.

Trait Implementations

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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<Error> for Error

fn from(source: Error) -> Error

Converts to this type from the input type.