How do I change the module type in IntelliJ

I have created a project from maven using mvn idea:idea. I recreate the project whenever there is a significant change to the pom files.

Sometimes after recreating, when 开发者_开发知识库I open IntelliJ it tells me that the modules have an unknown type so they will be treated as Unknown Modules.

1. How do I changes these modules to be the proper type?
2. Can anyone direct me to documentation about how to specify the module type so that idea:idea will generate the modules properly?

Thanks :)

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mvn idea:idea generated projects are not supported, please use the built-in IDEA Maven support instead, it works much better and you have an option to import changed Maven projects automatically or manually.