How to make gradle generate a valid pom.xml file at the root of a project for maven users?

You can use the gradle maven plugin. This adds the pom convention method to your project, which you can use in a task to generate a pom.xml file, like

task writeNewPom {
    doLast {
        pom {
            project {
                groupId 'org.example'
                artifactId 'test'
                version '1.0.0'
                inceptionYear '2008'
                licenses {
                    license {
                        name 'The Apache Software License, Version 2.0'
                        url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
                        distribution 'repo'
                    }
                }
            }
        }.writeTo("pom.xml")
    }
}

Then you call gradle createPom to generate the pom.xml in the project root. Of all the things in the pom definition, you should really provide groupId, artifactId and version, other thins like licenses are not that important.

You can also look at this example for a project definition with some dependencies, and try running it to see what it produces.

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