Can't specify an object for library for differing names per targets

As per the documentation:

https://webpack.js.org/configuration/output/#outputlibrary

// Since webpack 3.1.0, you may specify an object for library for differing names per targets:
module.exports = {
  //...
  output: {
    library: {
      root: 'MyLibrary',
      amd: 'my-library',
      commonjs: 'my-common-library',
    },
    libraryTarget: 'umd',
  },
};
libraryTarget: 'system'

However, using

    library: {
      root: 'MyLibrary',
      amd: 'my-library',
      commonjs: 'my-common-library',
    },

Throws an error with AssignLibraryPlugin: https://github.com/webpack/webpack/blob/master/lib/library/AssignLibraryPlugin.js#L126

Library name must be a string, string array or unset

It looks like the normalized library options passed into parseOptions is merging everything under name:

{
   type: 'this',
   auxiliaryComment: undefined,
   export: undefined,
   name: {
     amd: 'my-library',
     commonjs: 'my-common-library',
     root: 'MyLibrary'
   },
   umdNamedDefine: undefined
 }

Note that it’s a bit strange that the type is this, even though I pass libraryTarget: 'umd'

As a result it ends up going to AssignLibraryPlugin:

https://github.com/webpack/webpack/blob/547b4d8deb75355bf5695349fdcc3830ec22d68f/lib/library/EnableLibraryPlugin.js#L115

Other relevant information: webpack version:
Node.js version: v12.16.1 Operating System: Linux

[jqrun]

Just updating, it was 100% an issue in our repo, we had been mutating somewhere where we shouldn’t have, and a stray config ended up with type: ‘this’ instead of type: ‘umd’, which branched to the wrong plugin (in this case, AssignLibraryPlugin).

Will be better about following the template and reproducer guidelines next time!

[jqrun]

Looks like I wasn’t able to create a minimal reproducer, so there may be other configuration issues I have to figure out first, sorry about that! Will re-open if I’m able to distill the right context