denoland/deno · error

LAUFEY cache dir has no parent

Error message

LAUFEY cache dir has no parent: {}

What it means

Before extracting the downloaded laufey archive, the code creates the parent of the target cache directory with fs::create_dir_all(parent). Path::parent() returns None only for paths with no parent component — the filesystem root '/' or a bare prefix like 'laufey:' on Windows — so this error signals a degenerate cache-directory path rather than a normal missing directory.

Solutions

1. Check the cache-related environment variables (e.g. DENO_DIR) in the failing shell and make sure they point at a normal directory like ~/.cache/deno.
2. Unset the offending variable and let deno pick its default cache location.
3. If it persists with defaults, inspect how the cache path is derived for your platform and report it as a bug.

Example fix

# before
export DENO_DIR=/          # cache dir collapses to a parentless path
# error: LAUFEY cache dir has no parent: /

# after
unset DENO_DIR              # or: export DENO_DIR="$HOME/.cache/deno"

# Validate the cache root before running: it must be a normal, parented directory
case "${DENO_DIR:-$HOME/.cache/deno}" in
  /|""|*[!/]/*/) ;;
  *) test -d "${DENO_DIR:-$HOME/.cache/deno}" || echo "cache dir missing (will be created)" ;;
esac
# simplest guard: refuse degenerate values
test "${DENO_DIR:-x}" != "/" || { echo 'DENO_DIR must not be /'; exit 1; }

When it happens

Trigger: The computed laufey cache dir resolves to '/' or another parentless path, which in practice requires a broken cache-root configuration (e.g. DENO_DIR or an equivalent cache env var set to '/' or to a Windows drive prefix) rather than anything the download itself can cause.

Common situations: An env var pointing the deno cache at the filesystem root; a container image where the cache dir was computed from an unset HOME that collapsed to a degenerate path; essentially never seen with a correctly configured environment.

Related errors

• : failed to open for append
• ERR_INVALID_ARG_TYPE
• failed to atomic-rename LAUFEY cache to
• failed to open cache db at
• failed to open in-memory cache db

AI-assisted analysis of denoland/deno@f7822238ca (2026-08-20). Data as JSON: /api/errors/7c3d7ec2cdd16a6d. Report an issue: GitHub.

Appendix: source

Thrown at cli/tools/desktop.rs:2000

      .await
      .with_context(|| format!("failed to download {url}"))?;
    let data = response
      .into_maybe_bytes()?
      .ok_or_else(|| deno_core::anyhow::anyhow!("empty response from {url}"))?;

    let actual =
      faster_hex::hex_string(&sha2::Sha256::digest(&data)).to_lowercase();
    let expected_lc = expected.to_lowercase();
    if actual != expected_lc {
      // Include the URL in the bail: an attacker who poisoned a redirect
      // would otherwise be invisible in the failure log.
      bail!(
        "checksum mismatch for {archive} (downloaded from {url})\n  expected: {expected_lc}\n  actual:   {actual}"
      );
    }

    let parent = dir.parent().ok_or_else(|| {
      deno_core::anyhow::anyhow!(
        "LAUFEY cache dir has no parent: {}",
        dir.display()
      )
    })?;
    std::fs::create_dir_all(parent)?;

    // Stage extraction in a sibling tempdir so concurrent `deno desktop`
    // builds don't see (or stomp on) a half-populated `dir` while one
    // is mid-extract. tempfile's cleanup-on-drop covers panic /
    // early-return paths; on the happy path we consume the TempDir via
    // `into_path` so the rename below sees a real directory.
    let staging = tempfile::Builder::new()
      .prefix(".staging-")
      .tempdir_in(parent)
      .with_context(|| {
        format!("failed to stage tempdir in {}", parent.display())
      })?;

View on GitHub (pinned to f7822238ca)