janhq/jan · error · Error

Unsupported platform: ${platform}

Error message

Unsupported platform: ${platform}

What it means

Thrown by getPlatformArch() in scripts/download-bin.mjs when os.platform() returns a value other than 'darwin', 'linux', or 'win32'. The binary-fetch step (bun, uv, sqlite-vec) only ships prebuilt assets for those three OSes, so any other platform aborts the setup rather than downloading a wrong-arch binary.

Source

Thrown at scripts/download-bin.mjs:148

  const arch = os.arch() // 'x64', 'arm64', etc.

  let bunPlatform, uvPlatform

  if (platform === 'darwin') {
    bunPlatform = arch === 'arm64' ? 'darwin-aarch64' : 'darwin-x64'
    uvPlatform =
      arch === 'arm64' ? 'aarch64-apple-darwin' : 'x86_64-apple-darwin'
  } else if (platform === 'linux') {
    bunPlatform = arch === 'arm64' ? 'linux-aarch64' : 'linux-x64'
    uvPlatform =
      arch === 'arm64'
        ? 'aarch64-unknown-linux-gnu'
        : 'x86_64-unknown-linux-gnu'
  } else if (platform === 'win32') {
    bunPlatform = 'windows-x64' // Bun has limited Windows support
    uvPlatform = 'x86_64-pc-windows-msvc'
  } else {
    throw new Error(`Unsupported platform: ${platform}`)
  }

  return { bunPlatform, uvPlatform }
}

async function main() {
  if (process.env.SKIP_BINARIES) {
    console.log('Skipping binaries download.')
    process.exit(0)
  }
  console.log('Starting main function')
  const platform = os.platform()
  const { bunPlatform, uvPlatform } = getPlatformArch()
  console.log(`bunPlatform: ${bunPlatform}, uvPlatform: ${uvPlatform}`)

  const binDir = 'src-tauri/resources/bin'
  const tempBinDir = 'scripts/dist'
  const bunPath = `${tempBinDir}/bun-${bunPlatform}.zip`

View on GitHub (pinned to fad3f12a14)

Solutions

1. Run the setup on a supported platform (macOS, Linux, or Windows).
2. Set SKIP_BINARIES=1 to skip the download step if binaries are provided another way.
3. Manually place bun/uv binaries in scripts/dist matching the expected naming and bypass the script.
4. Extend getPlatformArch to map your platform if you can self-host the prebuilts.

Example fix

// before
const { bunPlatform, uvPlatform } = getPlatformArch()

// after (run)
SKIP_BINARIES=1 node scripts/download-bin.mjs

// or extend the function for your platform (e.g. freebsd) before calling

import os from 'os'
const SUPPORTED = new Set(['darwin', 'linux', 'win32'])
if (!SUPPORTED.has(os.platform())) {
  if (!process.env.SKIP_BINARIES) {
    throw new Error(`Set SKIP_BINARIES=1 or run on macOS/Linux/Windows (got ${os.platform()})`)
  }
}

When it happens

Trigger: Running `node scripts/download-bin.mjs` on FreeBSD, OpenBSD, SunOS/Solaris, AIX, or Android; running under a Node build that reports an unexpected platform string.

Common situations: Building on an uncommon OS; CI on a minimal container whose os.platform() is unexpected; attempting a native build instead of using the download path.

Related errors

• Platform {platform.system()} not supported
• No supported backend binaries found for this system. Backend
• MLX engine not found
• Extension does not support CUDA runtime installation

AI-assisted analysis of janhq/jan@fad3f12a14 (2026-08-12). Data as JSON: /api/errors/5b54b9d61ef4b94a. Report an issue: GitHub.