moeru-ai/airi · error · Error

Failed to ensure MediaPipe WASM assets: ${wasmOutputDir} is

Error message

Failed to ensure MediaPipe WASM assets: ${wasmOutputDir} is empty

What it means

Thrown by prepare-tasks.ts when, after fs.mkdir and fs.cp of the @mediapipe/tasks-vision/wasm directory into tasks/assets/wasm, the destination readdir returns an empty array. The WASM files are required at runtime by FilesetResolver.forVisionTasks, so an empty copy means the backend cannot initialize.

Source

Thrown at packages/model-driver-mediapipe/tasks/prepare-tasks.ts:99

await fs.mkdir(assetsRoot, { recursive: true })

for (const { key, source, outputPath } of taskTargets) {
  if (await isUsableFile(outputPath)) {
    console.log(`MediaPipe vision task asset for ${key} already exists at ${outputPath}, skipping download.`)
    continue
  }
  await downloadAsset(key, source, outputPath)

  if (!await isUsableFile(outputPath))
    throw new Error(`Failed to ensure MediaPipe vision task asset for ${key}: missing or empty file at ${outputPath}`)
}

await fs.mkdir(wasmOutputDir, { recursive: true })
await fs.cp(wasmSourceDir, wasmOutputDir, { recursive: true, force: true })

const wasmEntries = await fs.readdir(wasmOutputDir)
if (!wasmEntries.length)
  throw new Error(`Failed to ensure MediaPipe WASM assets: ${wasmOutputDir} is empty`)

console.log('All MediaPipe vision task assets are prepared.')

View on GitHub (pinned to 27111382b4)

Solutions

1. Verify packages/model-driver-mediapipe/node_modules/@mediapipe/tasks-vision/wasm exists and contains .wasm files.
2. Reinstall dependencies: pnpm install --force in the package, then rerun prepare-assets.
3. If the wasm dir is hoisted, adjust the wasmSourceDir resolution or pin @mediapipe/tasks-vision as a direct dependency.
4. Avoid running clean steps that wipe tasks/assets between cp and the readdir check.

Example fix

# before
ls node_modules/@mediapipe/tasks-vision/wasm  # empty
# after
pnpm -F @proj-airi/model-driver-mediapipe install --force
ls node_modules/@mediapipe/tasks-vision/wasm  # vision_packed_assets_loader.js, *.wasm ...
pnpm -F @proj-airi/model-driver-mediapipe prepare-assets

import { readdir } from 'node:fs/promises'
import { existsSync } from 'node:fs'

const wasmSrc = 'node_modules/@mediapipe/tasks-vision/wasm'
if (!existsSync(wasmSrc) || (await readdir(wasmSrc)).length === 0) {
  throw new Error('@mediapipe/tasks-vision wasm dir missing; run pnpm install --force')
}

try {
  await import('./prepare-tasks')
} catch (error) {
  if (error instanceof Error && /WASM assets.*is empty/.test(error.message)) {
    // reinstall the dependency and rerun prepare-assets
  } else throw error
}

When it happens

Trigger: fs.cp(wasmSourceDir, wasmOutputDir, { recursive: true, force: true }) silently copied nothing because wasmSourceDir was empty or missing; node_modules/@mediapipe/tasks-vision/wasm was pruned by a monorepo hoist or not populated because @mediapipe/tasks-vision is not installed at the expected location.

Common situations: pnpm hoisting moved the wasm dir elsewhere; a pruned/lite install omitted optional files; the tasks-vision package version changed its layout; the cp target was cleared by a clean step between cp and readdir; building from a tarball where node_modules is incomplete.

Related errors

• Failed to download MediaPipe vision task asset for ${key} af
• Failed to ensure MediaPipe vision task asset for ${key}: mis
• Godot stage exported binary not found. Expected at: ${join(p
• Invalid semver: ${version}
• Prerelease sequence overflow for ${stage}: ${sequence} excee

AI-assisted analysis of moeru-ai/airi@27111382b4 (2026-08-12). Data as JSON: /api/errors/430c1a235429d62c. Report an issue: GitHub.