rtk-ai/rtk · error

go: no subcommand specified

Error message

go: no subcommand specified

What it means

RTK's go handler run_other bails when the args slice is empty, before the `go tool` interception and subcommand forwarding run. A bare `rtk go` names no Go verb (build, test, vet...), so there is nothing to proxy or filter.

Source

Thrown at src/cmds/go/go_cmd.rs:128

        cmd.arg(arg);
    }

    if verbose > 0 {
        eprintln!("Running: go vet {}", args.join(" "));
    }

    runner::run_filtered(
        cmd,
        "go vet",
        &args.join(" "),
        filter_go_vet,
        crate::core::runner::RunOptions::with_tee("go_vet"),
    )
}

pub fn run_other(args: &[OsString], verbose: u8) -> Result<i32> {
    if args.is_empty() {
        anyhow::bail!("go: no subcommand specified");
    }

    // Intercept: `go tool <known>` invocations for filtered output
    if let Some((tool, tool_args)) = match_go_tool(args) {
        match tool {
            GoTool::GolangciLint => return run_go_tool_golangci_lint(tool_args, verbose),
        }
    }

    let timer = tracking::TimedExecution::start();

    let subcommand = args[0].to_string_lossy();
    let mut cmd = resolved_command("go");
    cmd.arg(&*subcommand);

    for arg in &args[1..] {
        cmd.arg(arg);
    }

View on GitHub (pinned to d977e1c316)

Solutions

  1. Name the verb explicitly: `rtk go build ./...`, `rtk go test ./...`, `rtk go vet ./...`
  2. Delegate the bare invocation: `rtk proxy go` or `go help`
  3. Guard dynamic invocation: verify the verb variable is non-empty before calling rtk

Example fix

# before
rtk go                # bail!("go: no subcommand specified")

# after
rtk go build ./...
rtk go test ./... -run regex_filter
Defensive patterns

Strategy: validation

Validate before calling

bash:
if [ $# -eq 0 ]; then
  echo "usage: rtk go <verb> [args...]" >&2
  exit 2
fi
rtk go "$@"

Type guard

rust:
fn has_go_verb(args: &[std::ffi::OsString]) -> bool {
    !args.is_empty()
}

Try / catch

rust:
if let Err(e) = go_cmd::run_other(&args, verbose) {
    if e.to_string().contains("go: no subcommand specified") {
        eprintln!("usage: rtk go <verb> (build | test | vet | run | ...)");
        std::process::exit(2);
    }
    return Err(e);
}

Prevention

When it happens

Trigger: Running `rtk go` with zero arguments (src/cmds/go/go_cmd.rs:129). Also wrappers forwarding an empty array, or `rtk go $GO_ARGS` with GO_ARGS empty.

Common situations: Makefile targets like `rtk go $(GOFLAGS) build` where GOFLAGS is empty and build is accidentally dropped; CI matrices generating the verb conditionally; agents invoking the bare command while probing.

Related errors

AI-assisted analysis of rtk-ai/rtk@d977e1c316 (2026-08-16). Data as JSON: /api/errors/04f25d650526c0b4. Report an issue: GitHub.