oven-sh/bun · error · Error

[azure] Command failed (exit ${result.exitCode}): ${command.

Error message

[azure] Command failed (exit ${result.exitCode}): ${command.join(" ")}\n${msg}

What it means

Thrown by spawnSafeFn in the Azure provider when an Azure Run Command invocation is judged failed. Failure is detected solely from displayStatus === "Provisioning failed" because stderr routinely carries harmless output (rustup progress, cargo warnings, PowerShell Write-Warning). The message embeds the joined command plus the output tail — Run Command only returns the last 4096 bytes.

Source

Thrown at scripts/azure.mjs:545

      const values = result?.value ?? [];
      const stdout = values[0]?.message ?? "";
      const stderr = values[1]?.message ?? "";
      if (opts?.stdio === "inherit") {
        if (stdout) process.stdout.write(stdout);
        if (stderr) process.stderr.write(stderr);
      }
      // Only use displayStatus to detect errors — stderr often contains non-error
      // output (rustup progress, cargo warnings, PowerShell Write-Warning, etc.)
      const hasError = values.some(v => v?.displayStatus === "Provisioning failed");
      const exitCode = hasError ? 1 : 0;
      return { exitCode, stdout, stderr };
    };

    const spawnSafeFn = async (command, opts) => {
      const result = await spawnFn(command, opts);
      if (result.exitCode !== 0) {
        const msg = result.stderr || result.stdout || "Unknown error";
        throw new Error(`[azure] Command failed (exit ${result.exitCode}): ${command.join(" ")}\n${msg}`);
      }
      return result;
    };
    const upload = async (source, destination) => {
      // Read the file locally and write it on the VM via Run Command
      const { readFileSync } = await import("node:fs");
      const content = readFileSync(source, "utf-8");
      // Escape for PowerShell — use base64 to avoid escaping issues
      const b64 = Buffer.from(content).toString("base64");
      const script = [
        `$bytes = [Convert]::FromBase64String('${b64}')`,
        `$dir = Split-Path '${destination}' -Parent`,
        `if (-not (Test-Path $dir)) { New-Item -Path $dir -ItemType Directory -Force | Out-Null }`,
        `[IO.File]::WriteAllBytes('${destination}', $bytes)`,
        `Write-Host "Uploaded to ${destination} ($($bytes.Length) bytes)"`,
      ];
      console.log(`[azure] Uploading ${source} -> ${destination}`);
      await runCommand(vmName, script);

View on GitHub (pinned to 8c5296ac45)

Solutions

Read the command and output tail embedded in the message to identify the failing step
Reproduce on the VM manually via az vm run-command invoke on the same machine
Fix the underlying build/script failure — this error only surfaces it
If the 4096-byte tail truncates the useful part, tee full output to a file on the VM and fetch it with a follow-up Run Command

Defensive patterns

Strategy: try-catch

Try / catch

try {
  await spawnSafe(["cargo", "build"], {});
} catch (e) {
  if (String(e.message).startsWith("[azure] Command failed")) {
    // message body already carries the command and the last 4096 bytes of output;
    // persist the full log before the VM is torn down
    await upload("build.log", "C:/logs/build.log");
  }
  throw e;
}

Prevention

Tee remote command output to a file on the VM, not just stdout
Remember stderr content is ignored for error detection — only displayStatus decides
Keep remote steps small so a 4096-byte tail is enough to diagnose

When it happens

Trigger: Any remote step (rustup install, cargo build, PowerShell provisioning script) exits non-zero on the Windows VM, which Azure records as Provisioning failed for the Run Command extension.

Common situations: Rust toolchain install failing on a fresh VM; cargo build errors from source regressions or OOM on the Standard_D4ds_v6/D4pds_v6 size; PowerShell scripts terminating mid-run; disk full on the temp VM.

Related errors

AI-assisted analysis of oven-sh/bun@8c5296ac45 (2026-08-16). Data as JSON: /api/errors/93470ccaf48308d0. Report an issue: GitHub.