Caused by: java.lang.NullPointerException at java.util.Hashtable$Entry.setValue (Hashtable.java:1286) at org.apache.maven.model.interpolation.StringVisitorModelInterpolator$ModelVisitor.visit (StringVisitorModelInterpolator.java:1429)

Seems to be resolved in 3.8.4. I'm now seeing a proper error message: Resolving expression: '${project.version}': Detected the following recursive expression cycle in 'project.version': [version, revision] @ org.example:foo:${revision}, /experiment/pom.xml -> [Help 2]