denoland/deno · error

invalid socket address

Error message

invalid socket address

What it means

connect_to_socket() in ext/cron/socket.rs accepts exactly three address forms: 'tcp:<addr>', 'unix:<path>' (non-Windows builds), and 'vsock:<cid>:<port>' (linux/android/macos builds). Any other value — unknown scheme, missing scheme, or a scheme compiled out for the platform — falls through to the catch-all arm and returns io::ErrorKind::InvalidInput 'invalid socket address'. The address comes from DENO_UNSTABLE_CRON_SOCK.

Source

Thrown at ext/cron/socket.rs:407

            std::io::ErrorKind::InvalidInput,
            "invalid vsock cid",
          )
        })?
      };
      let port = port.parse().map_err(|_| {
        std::io::Error::new(
          std::io::ErrorKind::InvalidInput,
          "invalid vsock port",
        )
      })?;
      let stream = tokio::time::timeout(
        std::time::Duration::from_secs(5),
        VsockStream::connect(VsockAddr::new(cid, port)),
      )
      .await??;
      Ok(SocketStream::Vsock(stream))
    }
    _ => Err(std::io::Error::new(
      std::io::ErrorKind::InvalidInput,
      "invalid socket address",
    )),
  }
}

async fn register_cron(
  socket_writer: &mut BufWriter<impl tokio::io::AsyncWrite + Unpin>,
  spec: &CronSpec,
) -> Result<(), std::io::Error> {
  let cron = CronRegistration {
    name: &spec.name,
    schedule: &spec.cron_schedule,
    backoff_schedule: spec.backoff_schedule.as_deref(),
  };

  let msg = OutboundMessage::Register { crons: &[cron] };

View on GitHub (pinned to 9ad36f7a2c)

Solutions

1. Prefix the address with a supported scheme: 'tcp:127.0.0.1:5000'
2. Use 'unix:/path/to/socket' for Unix domain sockets (not available on Windows)
3. Use 'vsock:cid:port' for AF_VSOCK schedulers on linux/android/macos
4. Leave DENO_UNSTABLE_CRON_SOCK unset to use the built-in local cron handler

Example fix

# before
DENO_UNSTABLE_CRON_SOCK='localhost:5000' deno run app.ts
# Error: invalid socket address

# after
DENO_UNSTABLE_CRON_SOCK='tcp:localhost:5000' deno run app.ts

const addr = Deno.env.get('DENO_UNSTABLE_CRON_SOCK')?.trim() ?? '';
const okSchemes = /^(tcp:|unix:|vsock:)/;
if (addr && !okSchemes.test(addr)) {
  throw new Error(
    `Unsupported cron socket address '${addr}'; expected tcp:host:port, unix:/path, or vsock:cid:port`,
  );
}
if (addr.startsWith('unix:') && Deno.build.os === 'windows') {
  throw new Error('unix: cron sockets are not supported on Windows');
}

When it happens

Trigger: DENO_UNSTABLE_CRON_SOCK='localhost:5000' (no tcp: prefix), 'udp:127.0.0.1:53' (unsupported scheme), 'http://sched:5000', '' (empty string), 'tcp' with no colon at all, or 'unix:/tmp/cron.sock' on Windows where the unix arm is not compiled in.

Common situations: Assuming the variable takes a plain host:port; forgetting the scheme prefix; attempting a Unix-domain-socket scheduler on a Windows host; copy-pasting a URL instead of a socket address.

Related errors

• invalid vsock cid
• invalid vsock port
• Can't convert url ("{}") to filename.
• Can't convert url ("{}") to filename.
• invalid value '{v}' for '{flag}=<HOST_AND_PORT>': {e}

AI-assisted analysis of denoland/deno@9ad36f7a2c (2026-08-20). Data as JSON: /api/errors/5b0f76f5c8b7f495. Report an issue: GitHub.