Do not fail on missing sources jar if there is no src directory for the jar

[ge0ffrey]

I am trying to release with JReleaser to Maven Central and getting these kinds of errors from pomchecker:

[ERROR] [nexus2] optaplanner-spring-boot-starter-8.36.0.Alpha1-sources.jar is missing

The sources plugin is active and Maven Central has accepted this artifact for years.

However this module is special:

• optaplanner-spring-boot-starter has no src directory. It just depends on optaplanner-spring-boot-autoconfigure, optaplanner-core and optaplanner-persistence-jackson. So the maven sources plugin doesn't create a sources jar.

See also https://github.com/jreleaser/jreleaser/discussions/1287

[aalmiray]

How are you able to publish without Maven Central failing on -sources.jar and -javadoc.jar? I thought those were hard requirements for a pom whose packaging is set to jar or if it uses the default packaging (which is jar).

[aalmiray]

PomChecker does not validate if -sources.jar is missing. It only checks pom files.