Opaque webpack errors after upgrading to v3

[giantrobotbee]

Hi there, I'm sure this isn't a super good question, but I'm also low on leads here. I've gone ahead and bumped everything to the latest using the yarn upgrader as per the documentation.

I go to spin up my app and I'm getting a very vague error from Webpack.

   - configuration.entry should be an non-empty object.
     -> Multiple entry bundles are created. The key is the chunk name. The value can be a string or an array.```

I can provide as much info as would be helpful to debug, but ultimately I'm just looking for any leads on where to start dealing with this, because so far this is seriously unhelpful.

Any help is seriously appreciated. Thanks.

[KyleAMathews]

What plugins are you using? It's possible one hasn't been updated for webpack 5 yet. You can check their issue queues to see about Gatsby v3 compatability.

[giantrobotbee]

		"gatsby-cli": "^3.8.0",
		"gatsby-image": "^3.8.0",
		"gatsby-plugin-create-client-paths": "^3.8.0",
		"gatsby-plugin-google-tagmanager": "^3.8.0",
		"gatsby-plugin-manifest": "^3.8.0",
		"gatsby-plugin-mixpanel": "^3.3.0",
		"gatsby-plugin-react-helmet": "^4.8.0",
		"gatsby-plugin-react-svg": "^3.0.1",
		"gatsby-plugin-sharp": "^3.8.0",
		"gatsby-plugin-styled-components": "^4.8.0",
		"gatsby-plugin-typescript": "^3.8.0",
		"gatsby-source-buttercms": "^2.1.3",
		"gatsby-source-filesystem": "^3.8.0",
		"gatsby-source-graphql": "^3.8.0",
		"gatsby-transformer-sharp": "^3.8.0",```

Sifting around these are the remaining plugins that do all claim to support Gatsby v3 and yet I'm still getting the error.

For context we do have our own Webpack injection in gatsby-node.js, but commenting it out still yields the same error so I don't think it's coming from us.

[giantrobotbee]

I have actually removed all plugins and relevant configurations and am getting the exact same error, just at an earlier point in the build.

[giantrobotbee]

In case anyone comes across this thread with a similar problem, here's what was causing me issues:

		"webpack": "~5.41.1"
	},```

This was previously on 4.x, needed to bump it and nombom to get things happy.

[graysonhicks]

Thanks @giantrobotbee ! Can you mark this as answered?