Parcel library setup not working in Lerna package

[diego-hourly]

🐛 bug report

I'm setting up a parcel library for a react component by using https://parceljs.org/getting-started/library/ and exporting a simple component in a Lerna monorepo (here is a sample repo). But got this error.

> parcel watch

🚨 Build failed.

@parcel/packager-js: Asset was skipped or not found.

  AssertionError [ERR_ASSERTION]: Asset was skipped or not found.
  at ScopeHoistingPackager.getSymbolResolution

🎛 Configuration (.babelrc, package.json, cli command)

package.json

{
  "name": "poc",
  "private": true,
  "devDependencies": {
    "lerna": "^4.0.0"
  },
  "scripts": {
    "start:common": "lerna exec --scope @poc/common -- npm start",
    "start:client": "lerna exec --scope @poc/client -- npm start",
    "build": "lerna exec -- npm run build",
    "postinstall": "lerna clean -y && lerna bootstrap"
  }
}

packages/commons/package.json:

{
  "name": "@poc/common",
  "version": "1.0.0",
  "source": "src/index.js",
  "main": "dist/main.js",
  "scripts": {
    "start": "parcel watch",
    "build": "parcel build"
  },
  "dependencies": {
    "@parcel/transformer-react-refresh-wrap": "^2.0.1",
    "parcel": "^2.0.1",
    "react": "^17.0.2",
    "react-dom": "^17.0.2"
  }
}

packages/client/package.json

{
  "name": "@poc/client",
  "version": "1.0.0",
  "dependencies": {
    "@poc/common": "1.0.0",
    "react": "^17.0.2",
    "react-dom": "^17.0.2"
  },
  "devDependencies": {
    "react-scripts": "5.0.0"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build"
  }
}

NOTE: not sure why is @parcel/transformer-react-refresh-wrap required but if not included in dependencies section the cli throws an error

NOTE 2: running npm run build works like a charm

cli command

First install dependencies and then

start:common # which is basically parcel watch

🤔 Expected Behavior

The app should watch and compile the source code

😯 Current Behavior

CLI throws this error:

> parcel watch

🚨 Build failed.

@parcel/packager-js: Asset was skipped or not found.

  AssertionError [ERR_ASSERTION]: Asset was skipped or not found.
  at ScopeHoistingPackager.getSymbolResolution
  (/Users/diegotoro/code/poc-parcel/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:716:29)
  at /Users/diegotoro/code/poc-parcel/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:820:31
  at Array.map (<anonymous>)
  at ScopeHoistingPackager.buildAssetPrelude
  (/Users/diegotoro/code/poc-parcel/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:819:37)
  at ScopeHoistingPackager.buildAsset
  (/Users/diegotoro/code/poc-parcel/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:382:48)
  at ScopeHoistingPackager.visitAsset
  (/Users/diegotoro/code/poc-parcel/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:341:17)
  at /Users/diegotoro/code/poc-parcel/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:153:40
  at /Users/diegotoro/code/poc-parcel/node_modules/@parcel/graph/lib/Graph.js:520:16
  at /Users/diegotoro/code/poc-parcel/node_modules/@parcel/graph/lib/Graph.js:520:16
  at /Users/diegotoro/code/poc-parcel/node_modules/@parcel/graph/lib/Graph.js:520:16

💁 Possible Solution

🔦 Context

Trying to create a common package in a Lerna monorepo.

💻 Code Sample

Here I created a simple sample of the setup I have.

https://github.com/diego-toro/poc-monorepo-parcel

🌍 Your Environment

Software	Version(s)
Parcel	2.0.1
Node	v14.18.2
npm	6.14.15
Operating System	MacOS 11.6.1

[overtone1000]

I'm also seeing this error with a web app after I migrated react from v16 to v17 and material-ui from v4 to v5. parcel watch worked prior to this migration but now yields very similar error output to what you report.

> parcel watch ./src/*.html --dist-dir ../../backend/static --cache-dir ../build/cache --target browser

Debugger attached.
Debugger attached.
Debugger attached.
🚨 Build failed.

@parcel/packager-js: Asset was skipped or not found.

  AssertionError [ERR_ASSERTION]: Asset was skipped or not found.
  at ScopeHoistingPackager.getSymbolResolution (/home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:732:29)
  at /home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:836:31
  at Array.map (<anonymous>)
  at ScopeHoistingPackager.buildAssetPrelude (/home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:835:37)
  at ScopeHoistingPackager.buildAsset (/home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:398:48)
  at ScopeHoistingPackager.visitAsset (/home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:357:17)
  at /home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:456:56
  at String.replace (<anonymous>)
  at ScopeHoistingPackager.buildAsset (/home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:420:19)
  at ScopeHoistingPackager.visitAsset (/home/tyler/repos/AutoScheda/SourceCode/frontend/v3/node_modules/@parcel/packager-js/lib/ScopeHoistingPackager.js:357:17)

parcel build also works fine for me. I'm not using the lerna package.

Software	Version(s)
Parcel	2.2.1
Node	14.16.1
npm	8.3.1
Operating System	Ubuntu 20.10
react	17.0.2
@mui/material	5.3.0

I haven't been able to narrow it down to a single component yet. The react version is the only thing we seem to have in common.

[lettertwo]

#7914 should resolve this.

[overtone1000]

@diego-hourly, did this fix work for you? My build target is browser, and I still see this error after upgrading to v2.4.1.

[lettertwo]

@overtone1000 the fix will be in the next release. You could try installing parcel@nightly if you want to try it before then.

[overtone1000]

🐑 Apologies, I mistakenly thought #7914 was merged into the latest release. Indeed, parcel version 2.0.0-nightly.1041 successfully builds this project with the parcel watch command. I'm seeing a "redeclaration of let _" error in the web console that doesn't occur when I build using the parcel build command. I'll test this again with the next release version.

Many thanks!