denoland/deno · error · anyhow::Error

Invalid YAML: {e}

Error message

Invalid YAML: {e}

What it means

Thrown while parsing pnpm-workspace.yaml for a Deno workspace that uses pnpm. Deno reuses the yaml_parser CST that powers `deno fmt` (no new YAML dependency); when that parser reports a syntax error, this message wraps it and appends the parser's position details after the colon.

Source

Thrown at cli/util/pnpm_workspace.rs:252

}

fn string_map_to_value(map: &IndexMap<String, String>) -> CstInputValue {
  CstInputValue::Object(
    map
      .iter()
      .map(|(k, v)| (k.clone(), CstInputValue::String(v.clone())))
      .collect(),
  )
}

// ===========================================================================
// pnpm-workspace.yaml parsing (via the yaml_parser CST already used by
// `deno fmt`, so no new YAML dependency is introduced).
// ===========================================================================

fn parse_pnpm_workspace(text: &str) -> Result<PnpmWorkspace, AnyError> {
  let tree = yaml_parser::parse(text)
    .map_err(|e| deno_core::anyhow::anyhow!("Invalid YAML: {e}"))?;
  let Some(root) = Root::cast(tree) else {
    return Ok(PnpmWorkspace::default());
  };
  let Some(block_map) = root
    .documents()
    .next()
    .and_then(|doc: Document| doc.block())
    .and_then(|block| block.block_map())
  else {
    return Ok(PnpmWorkspace::default());
  };

  let mut result = PnpmWorkspace::default();
  for entry in block_map.entries() {
    let Some(key) = entry.key().map(|k| k.syntax().clone()) else {
      continue;
    };
    let Some(key_name) = scalar_text(&key) else {

View on GitHub (pinned to 89f33cbef2)

Solutions

1. Fix the YAML syntax at the position reported after 'Invalid YAML:' (replace tabs with spaces, balance quotes and brackets)
2. Validate the file outside Deno, e.g. `pnpm install --lockfile-only` or a YAML linter, to confirm it parses
3. If the project does not actually use pnpm workspaces, delete or rename pnpm-workspace.yaml so Deno stops parsing it

Example fix

# pnpm-workspace.yaml (before) — tab-indented, invalid YAML
packages:
	- "apps/*"

# after — space-indented
packages:
  - "apps/*"

// CI pre-check: parse pnpm-workspace.yaml before any deno command
import { parse } from "jsr:@std/yaml";
try {
  parse(await Deno.readText("pnpm-workspace.yaml"));
  console.log("pnpm-workspace.yaml OK");
} catch (e) {
  console.error(`Invalid YAML: ${e}`);
  Deno.exit(1);
}

When it happens

Trigger: Any `deno` CLI command that loads workspace config (`deno install`, `deno run`, `deno task`, ...) when pnpm-workspace.yaml contains invalid YAML: tab indentation, unbalanced quotes or flow brackets ([/]), duplicate keys rejected by the parser, or a stray control character.

Common situations: Hand-editing the `packages:` list and mixing tabs with spaces; pasting YAML from docs or chat that includes smart quotes; a merge leaving an unbalanced bracket; editors inserting a BOM.

Related errors

• No bench modules found
• Task not found: {}
• The bench name can't be empty
• Unexpected 'name' field in options, bench name is already pr
• Unexpected second argument to Deno.bench()

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/fd201cb16e3e77e8. Report an issue: GitHub.