swc-project/swc · error · anyhow::Error

Failed to run cargo command

Error message

Failed to run cargo command

What it means

xtask's run_cmd helper spawns a child process (cargo, git, etc.), inherits stdin, waits for exit, and bails with this generic message whenever the child's exit status is non-success. The command line was already printed to stderr ('Running ...'), so the actual failure details live in the child's own output just above this error.

Source

Thrown at xtask/src/util/mod.rs:29

where
    F: FnOnce() -> Result<Ret>,
{
    op()
}

pub fn repository_root() -> Result<PathBuf> {
    let dir = env::var("CARGO_MANIFEST_DIR").context("failed to get manifest dir")?;
    Ok(Path::new(&*dir).parent().unwrap().to_path_buf())
}

pub fn run_cmd(cmd: &mut Command) -> Result<()> {
    eprintln!("Running {:?}", *cmd);
    cmd.stdin(Stdio::inherit());

    let status = cmd.status()?;

    if !status.success() {
        anyhow::bail!("Failed to run cargo command");
    }

    Ok(())
}

pub fn get_commit_for_core_version(version: &str, last: bool) -> Result<String> {
    wrap(|| {
        eprintln!("Getting commit for swc_core@v{version}");

        // We need to get the list of commits and pull requests which changed the
        // version of swc_core.
        let git_rev_list = Command::new("git")
            .current_dir(repository_root()?)
            .arg("rev-list")
            .arg("--branches")
            .arg("main")
            .arg("--")
            .arg("Cargo.lock")

View on GitHub (pinned to d7d7434666)

Solutions

1. Scroll up to the child command's own stderr/stdout - the real error is there; fix that underlying failure
2. Re-run the exact 'Running ...' command printed just above to reproduce it directly
3. For CI, ensure submodules are initialized (git submodule update --init --recursive) and the pinned toolchain is installed before invoking xtask

Example fix

# before: opaque failure
$ cargo xtask some-task
Error: Failed to run cargo command

# after: reproduce the printed command to see the cause
$ cargo build -p swc_core --all-features   # whatever 'Running ...' showed
# fix the underlying error, then re-run the xtask

# Shell: preflight the common causes before invoking xtask
git submodule update --init --recursive
cargo --version && rustc --version  # match pinned toolchain

# Shell: run xtask so the child's real error stays visible, then surface exit code
cargo xtask <task> 2>&1 | tee /tmp/xtask.log
status=${PIPESTATUS[0]}
if [ "$status" -ne 0 ]; then
  echo "xtask failed; the failing child command is the last 'Running ...' line above"
  exit "$status"
fi

When it happens

Trigger: Any xtask driver (bump-core-version, release, etc.) whose underlying cargo build/test/doc or git invocation exits nonzero - compile error in the workspace, failing test, git conflict, missing tool.

Common situations: Running cargo xtask commands locally on a dirty or broken tree; CI jobs invoking xtask where a nested cargo step fails; missing git submodules making a nested cargo invocation fail.

Related errors

• {message}; run `cargo codegen helpers` and commit the genera
• module string names unimplemented
• module string names unimplemented
• module string names unimplemented
• module string names unimplemented

AI-assisted analysis of swc-project/swc@d7d7434666 (2026-08-16). Data as JSON: /api/errors/73f807cbc43e7ebf. Report an issue: GitHub.