What causes "A deno.json file could not be found or created" in denoland/deno?

Create a deno.json first (echo '{}' > deno.json or deno init), then re-run

A deno.json file could not be found or created

Error message

A deno.json file could not be found or created

What it means

The script-approval command needs a deno.json to record which npm lifecycle scripts may run. If no deno.json exists, Deno first tries to create one; this error means that after the attempt the workspace still has no root deno.json — creation was declined, failed, or the discovered root is not a deno.json.

Source

Thrown at cli/tools/pm/approve_scripts.rs:52

struct ScriptCandidate {
  req: PackageReq,
  specifier: String,
  scripts: Vec<String>,
}

pub async fn approve_scripts(
  flags: Arc<Flags>,
  approve_flags: ApproveScriptsFlags,
) -> Result<(), AnyError> {
  let mut factory = CliFactory::from_flags(flags.clone());
  let mut options = factory.cli_options()?;
  if options.start_dir.member_or_root_deno_json().is_none() {
    factory = create_deno_json(&flags, options)?;
    options = factory.cli_options()?;
  }
  let deno_json = options.workspace().root_deno_json().ok_or_else(|| {
    anyhow::anyhow!("A deno.json file could not be found or created")
  })?;

  let deno_json_path = url_to_file_path(&deno_json.specifier)?;

  let mut config_updater =
    ConfigUpdater::new(ConfigKind::DenoJson, deno_json_path.clone())?;

  let allow_scripts_config = deno_json.to_allow_scripts_config()?;

  let (mut allow_list, mut deny_list) = match allow_scripts_config.allow {
    AllowScriptsValueConfig::All => {
      log::info!(
        "Lifecycle scripts are already allowed for all npm packages in the workspace.",
      );
      return Ok(());
    }
    AllowScriptsValueConfig::Limited(list) => (list, allow_scripts_config.deny),
  };

View on GitHub (pinned to 89f33cbef2)

Solutions

Create a deno.json first (echo '{}' > deno.json or deno init), then re-run
Run the command inside the directory where the root deno.json should live
Ensure the cwd is writable and the session is interactive if creation needs to prompt

Example fix

# before
$ deno approve-scripts   # no deno.json anywhere
# after
$ echo '{}' > deno.json && deno approve-scripts

Defensive patterns

Strategy: validation

Validate before calling

test -f deno.json || { echo 'no deno.json — creating one' >&2; echo '{}' > deno.json; }
deno approve-scripts

Prevention

Keep a minimal deno.json at the repo root even in hybrid npm/Deno projects
Run approval commands from the workspace root

When it happens

Trigger: Running the approval command in a directory governed only by package.json where deno.json creation fails (non-interactive terminal, read-only cwd) or the created config does not become a workspace root.

Common situations: npm-centric repos adopting Deno incrementally; CI pipelines with no TTY where an interactive creation prompt cannot be answered; workspaces whose root config is package.json.

Related errors

AI-assisted analysis of denoland/deno@89f33cbef2 (2026-08-16). Data as JSON: /api/errors/ee74b0cd6299b625. Report an issue: GitHub.