How to debug monorepo with: Bundle group cannot have more than one entry bundle of the same type

[lindskogen]

I downloaded the latest beta (2.0.0-beta.1).

We are using svg-as-react-component-imports so I needed to add a .parcelrc file:

{
  "extends": ["@parcel/config-default"],
  "transformers": {
    "*.svg": ["@parcel/transformer-svg-react"]
  }
}

Now I get this when I run yarn parcel packages/*.

@parcel/namer-default: Bundle group cannot have more than one entry bundle of the same type
AssertionError [ERR_ASSERTION]: Bundle group cannot have more than one entry bundle of the same type

How do I begin debugging this? Can I somehow get the original filenames of the conflicting bundles if I put a well-placed console.log somewhere?

Every package.json specifies their own types, module, source like so:

  "types": "dist/index.d.ts",
  "module": "dist/index.es.js",
  "source": "src/index.ts",

[mischnic]

Maybe logging entryBundlesOfType here (console.log(entryBundlesOfType.map(b => b.filePath));)?

parcel/packages/namers/default/src/DefaultNamer.js

Lines 26 to 35 in c4e494f

	if (bundle.isEntry) {
	let entryBundlesOfType = bundleGroupBundles.filter(
	b => b.isEntry && b.type === bundle.type,
	);
	assert(
	entryBundlesOfType.length === 1,
	// Otherwise, we'd end up naming two bundles the same thing.
	'Bundle group cannot have more than one entry bundle of the same type',
	);
	}

In the published npm package, it's in the lib folder:

https://unpkg.com/browse/@parcel/namer-default@2.0.0-beta.1/lib/DefaultNamer.js

[lindskogen]

It doesn't happen when I tried running parcel for every dir in packages:

find packages -type d -depth 1 -exec yarn parcel {} \;

[lindskogen]

It seems to happen when I build two packages A and B, when A depends on B and B has css files.

[TobiasSchikora]

Anything new? I have the same problems with parcel 2. See #6310.

[TobiasSchikora]

Nothing new? Problem still exists. See quick demo at #6310

[richardkmichael]

@mischnic I'm debugging this problem now too. Thanks for the tip to console.log in DefaultNamer.js.

I have found parcel serve is generating dist/index.css twice. It doesn't actually write dist/ though, so I'm unsure if the content of the two generated files is is different. I presume this data is in the LMDB cache, so I'll have a look there for hints about how the CSS is being generated.

FWIW, parcel build .. doesn't have this problem because it doesn't seem to be generating any CSS. I don't know why.

I have six CSS import lines in the entire project, i.e., import ....

• One CSS file imported in three different files
• A second CSS file imported in two different files
• A third CSS file imported in one file only

[S-unya]

I may have a little bit of new information here. I have this same problem, but if I remove either the source entry or the module entry from package.json, it works fine. My guess is that there are a number of assets that will be duplicated for the 2 output processes - in mine and @lindskogen 's case I think it is the svg assets.

I don't know of a work around for this apart from running parcel once for each output target, which seems inelegant.