The theme generator seems to have a bug related to lodash. If a component is created using npm run generate and the theme name contains multiple words as a single string, lodash creates a new themename.libraries.yml file using the theme name but separating the theme name by an underscore. For example, when I used the theme name drupal9_theme when prompted for my theme name when creating a new component, the generator created a new *.libraries.yml file called drupal_9_theme.libraries.yml.
Solution
Please remove lodash as this is not a requirement by a drupal theme. If lodash is required in a project, it can be added on that project.
The theme generator seems to have a bug related to lodash. If a component is created using
npm run generateand the theme name contains multiple words as a single string, lodash creates a newthemename.libraries.ymlfile using the theme name but separating the theme name by an underscore. For example, when I used the theme namedrupal9_themewhen prompted for my theme name when creating a new component, the generator created a new*.libraries.ymlfile calleddrupal_9_theme.libraries.yml.Solution