@gziolo --save-exact is not required and can totally be dropped from this PR. It's a personal preference that I thought it was worth promoting as a good practice. I'm fine removing that from the PR if that's controversial.

It might be something about the dependencies included by @wordpress/scripts. It's hard to judge based on Gutenberg because there are thousands of dependencies listed. I assume this is going to be no issue as soon as we have the default Webpack config included in the scripts exposed by the package we offer :)

The root problem seems related to babel-loader@8 requiring @babel/plugin-transform-react-jsx while babel-loader@7 requires babel-plugin-transform-jsx, which is a different thing, apparently. So depending on which version of babel-loader gets installed, the other dependencies need to be adjusted.

Do you know what is using Babel 6 specific packages causing babel-loader@7 to be pulled in?

@gziolo not sure I follow. Here's what I know:

• Installing babel-loader will pull the latest version (8). That version requires @babel/plugin-transform-react-jsx.
• If we wanted to use babel-plugin-transform-react-jsx we should explicitly install babel-loader@7.

I chose to go with the first option because that's what Gutenberg uses.

• If we wanted to use babel-plugin-transform-react-jsx we should explicitly install babel-loader@7.

Why would you want to install it in the first place?

I chose to go with the first option because that's what Gutenberg uses.

Yes, this is highly expected.