Error 422 when trying to deploy a maven plugin into Github Packages

[jorgeb1980]

Select Topic Area

Bug

Body

While trying to publish a maven plugin into Github Packages, I have found this error

Warning: Could not transfer metadata sample-plugin/maven-metadata.xml from/to github (https://maven.pkg.github.com/jorgeb1980/sample-maven-plugin): status code: 422, reason phrase: Unprocessable Entity (422)

This was previously reported here - please see https://github.com/jorgeb1980/sample-maven-plugin for sample code that hits the issue.

It seems that github's implementation of maven2 repository fails to parse legal maven-metadata.xml group-level files produced by maven-plugin-plugin. These files are documented in https://maven.apache.org/repositories/metadata.html#the-g-level-metadata and appear to be a cache of sorts for plugin abbreviations.

As far as I know, the generated file appears to be valid, and deployment is successful in OSS version of artifactory.

[jorgeb1980]

Some additional info in order to reproduce the bug:

• please check this successful run when, in the pom.xml, field packaging = jar
• please check a run that fails with the same code, only difference: in the pom.xml, packaging = maven-plugin

Differences between both commits: jorgeb1980/sample-maven-plugin@9ec48bc...cfb0237