denoland/deno · error · AnyError

vsock is not supported on this platform

Error message

vsock is not supported on this platform

What it means

Deno's OpenTelemetry OTLP connector can export telemetry over AF_VSOCK (guest-host sockets used in microVMs like Firecracker/gVisor) when `OTEL_DENO_VSOCK` is set. The vsock code is only compiled for android/linux/macos; on any other target — notably Windows — merely having the variable present makes the connector builder bail before telemetry starts.

Solutions

1. Unset the variable on Windows: `Remove-Item Env:OTEL_DENO_VSOCK` (or remove it from the .env/CI matrix for Windows jobs).
2. Use standard HTTP/gRPC OTLP export on Windows: set `OTEL_EXPORTER_OTLP_ENDPOINT` instead.
3. Keep `OTEL_DENO_VSOCK` only in Linux/macOS/Android deploy targets that actually provide AF_VSOCK.

Example fix

# before (PowerShell on Windows)
$env:OTEL_DENO_VSOCK = '3:4317'
deno run --otel app.ts
# error: vsock is not supported on this platform

# after
Remove-Item Env:OTEL_DENO_VSOCK
$env:OTEL_EXPORTER_OTLP_ENDPOINT = 'http://localhost:4317'
deno run --otel app.ts

// TypeScript/Deno: scrub platform-specific env before spawning
if (Deno.build.os === "windows" && Deno.env.has("OTEL_DENO_VSOCK")) {
  Deno.env.delete("OTEL_DENO_VSOCK");
}

When it happens

Trigger: Running Deno on Windows with `OTEL_DENO_VSOCK` present in the environment while telemetry is in use. The value does not matter on unsupported platforms; even an empty string triggers the bail (on supported platforms an empty string instead fails the cid:port parse).

Common situations: Environment blocks copied from Linux VM/microVM configs (e.g. `OTEL_DENO_VSOCK=3:4317` for a Firecracker guest) reused on a Windows dev box or CI runner; shared .env files applied across platforms.

Understand the failure class

Background: "unsupported platform" / "not supported on this platform" errors: what they mean and how to fix them — this error's family across 47 libraries.

Related errors

• invalid vsock addr
• APPDATA not set
• ContextManager can not be constructed
• Counter can only be incremented
• Failed to extract with

AI-assisted analysis of denoland/deno@9ad36f7a2c (2026-08-20). Data as JSON: /api/errors/63ecb30bb00fcf78. Report an issue: GitHub.

Appendix: source

Thrown at ext/telemetry/lib.rs:807

    inner: Client<Connector, Full<Bytes>>,
    timeout: Duration,
  }

  impl HyperClient {
    fn build_connector(
      sys: &impl FsRead,
    ) -> deno_core::anyhow::Result<Connector> {
      let connector = if let Some(tunnel) = get_tunnel() {
        Connector::Tunnel(tunnel.clone())
      } else if let Ok(addr) = std::env::var("OTEL_DENO_VSOCK") {
        #[cfg(not(any(
          target_os = "android",
          target_os = "linux",
          target_os = "macos"
        )))]
        {
          let _ = addr;
          deno_core::anyhow::bail!("vsock is not supported on this platform")
        }

        #[cfg(any(
          target_os = "android",
          target_os = "linux",
          target_os = "macos"
        ))]
        {
          let Some((cid, port)) = addr.split_once(':') else {
            deno_core::anyhow::bail!("invalid vsock addr");
          };
          let cid = if cid == "-1" { u32::MAX } else { cid.parse()? };
          let port = port.parse()?;
          let addr = VsockAddr::new(cid, port);
          Connector::Vsock(addr)
        }
      } else {
        let ca_certs = match std::env::var("OTEL_EXPORTER_OTLP_CERTIFICATE") {

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