What causes "configured" in gitbutlerapp/gitbutler?

Keep .stdin(Stdio::piped()) on the Command used to spawn hooks

configured

Error message

configured

What it means

run_pre_push() spawns the pre-push hook with .stdin(Stdio::piped()) (hooks.rs:270) and later grabs child.stdin with expect("configured"). std::process::Child::stdin is Some only when the command was configured for piped stdin; since the spawn setup does exactly that a few lines above, None is impossible unless the construction is refactored. The code below already tolerates the hook exiting early (BrokenPipe is ignored).

Source

Thrown at crates/gitbutler-repo/src/hooks.rs:283

            prep.command = gix::path::from_bstring(with_slashes_for_bash.into_owned()).into();
        }
        prep.arg(remote_name).arg(remote_url)
    })
    .current_dir(repo.workdir().unwrap_or(repo.git_dir()))
    .stdin(Stdio::piped())
    .spawn()?;

    {
        let remote_commit = repo
            .try_find_reference(&remote_tracking_branch.to_string())?
            .map(|mut reference| reference.peel_to_id().map(|id| id.detach()))
            .transpose()?
            .unwrap_or_else(|| repo.object_hash().null());
        // THIS IS WRONG: but is correct in the common case. This also is an issue when the ref is actually pushed,
        // but we can fix it when moving everything to `gix`.
        let local_tracking_branch_deduced =
            format!("refs/heads/{}", remote_tracking_branch.branch());
        let stdin = child.stdin.as_mut().expect("configured");
        let refspec = format!(
            "{local_tracking_branch_deduced} {local_commit} {remote_tracking_branch} {remote_commit}\n"
        );
        // Hooks may exit before reading stdin if they don't need the refspec info.
        // The actual success/failure is determined by the exit code via wait_with_output() below.
        if let Err(err) = stdin.write_all(refspec.as_bytes())
            && err.kind() != std::io::ErrorKind::BrokenPipe
        {
            return Err(err.into());
        }
    }

    let output = child.wait_with_output()?;
    if output.status.success() {
        Ok(HookResult::Success)
    } else {
        let error = join_output(
            output.stdout.to_str_lossy().into_owned(),

View on GitHub (pinned to caf1f223d3)

Solutions

Keep .stdin(Stdio::piped()) on the Command used to spawn hooks
Replace the expect with an explicit error so future refactors fail loudly with context (see exampleFix)
Keep the existing hook integration tests (crates/gitbutler-repo/tests/repo/hooks.rs) green so spawn regressions surface there

Example fix

// before
let stdin = child.stdin.as_mut().expect("configured");

// after
let Some(stdin) = child.stdin.as_mut() else {
    anyhow::bail!("pre-push hook was spawned without piped stdin");
};

Defensive patterns

Strategy: validation

Validate before calling

// When spawning hook processes, make the stdin contract explicit up front
let mut cmd: std::process::Command = /* ... */;
cmd.stdin(std::process::Stdio::piped()); // required: refspec is written to the hook
assert_eq!(cmd.get_stdin(), Some(&std::process::Stdio::piped()));

Try / catch

// Fail with context instead of panicking if the contract is broken
let Some(stdin) = child.stdin.as_mut() else {
    anyhow::bail!("hook was spawned without piped stdin");
};

Prevention

Keep .stdin(Stdio::piped()) adjacent to the spawn call for hooks
Handle BrokenPipe on writes - hooks may exit before reading stdin (already done here)
Cover hook execution paths with integration tests

When it happens

Trigger: Any pre-push hook execution (pushing a repo that has .git/hooks/pre-push or .husky/pre-push). The panic fires only if the .stdin(Stdio::piped()) line is removed or changed in the Command construction above.

Common situations: Refactors of the hook-spawning code that drop or conditionalize piped stdin. Not user-triggerable: a fast-exiting hook is handled by the BrokenPipe check that follows.

Related errors

AI-assisted analysis of gitbutlerapp/gitbutler@caf1f223d3 (2026-08-20). Data as JSON: /api/errors/45de0a4a883f1b49. Report an issue: GitHub.