Crate procpilot 

Production-grade subprocess runner with typed errors, retry, and timeout.

procpilot provides one entry point — the Cmd builder — covering every practical subprocess configuration. Errors are typed: RunError distinguishes spawn failure, non-zero exit, and timeout, each carrying the last 128 KiB of stdout/stderr for diagnosis.

Quick start

use std::time::Duration;
use procpilot::{Cmd, RunError};

let output = Cmd::new("git")
    .args(["show", "maybe-missing-ref"])
    .timeout(Duration::from_secs(30))
    .run();

match output {
    Ok(o) => println!("{}", o.stdout_lossy()),
    Err(RunError::NonZeroExit { .. }) => { /* ref not found */ }
    Err(e) => return Err(e.into()),
}

Features

• Typed errors: RunError variants for spawn / non-zero / timeout, with shell-quoted command display (secret-redacted via Cmd::secret).
• Stdin: Cmd::stdin accepts owned bytes (reusable across retries) or a boxed Read (one-shot).
• Stderr routing: Redirection covers capture, inherit, null, and file redirection.
• Timeout + deadline: Cmd::timeout for per-attempt, Cmd::deadline for overall wall-clock budget across retries.
• Retry with exponential backoff: Cmd::retry / Cmd::retry_when.
• Escape hatches: Cmd::before_spawn for pre-spawn hooks, Cmd::to_command to drop to raw std::process::Command.

Release history: CHANGELOG.md.

Structs

Cmd

Builder for a subprocess invocation or pipeline.

CmdDisplay

Owned snapshot of a command’s program + args, formatted shell-style on Display. For pipelines, renders each stage separated by |.

RetryPolicy

How retries are scheduled and which errors trigger them.

RunOutput

Captured output from a successful command.

SpawnedProcess

Handle to a spawned subprocess.

Enums

Redirection

Where a child process’s stderr (or stdout, when supported) goes.

RunError

Error type for subprocess execution.

StdinData

Input data to feed to a child process’s stdin.

Constants

STREAM_SUFFIX_SIZE

Maximum bytes of stdout/stderr retained on NonZeroExit and Timeout error variants. Anything beyond this is dropped from the front (FIFO), keeping the most recent output — usually the most relevant for debugging.

Functions

binary_available

Check whether a binary is available on PATH.

binary_version

Return a binary’s --version output, if available.

default_transient

Default transient-error predicate.

Type Aliases

BeforeSpawnHook

Hook invoked on std::process::Command immediately before each spawn attempt.