Conflict in plexus classes causes new-project to fail

[no project] bin $ cd ../..
[no project] forge $ mkdir workspace
[no project] forge $ cd workspace
[no project] workspace $ new-project
[named=The name of the new project (of type java.lang.String)]: foo
[topLevelPackage=The top level package for your Java source files [e.g: "com.example.project"] (of type java.lang.String)]: org.foo
Use [/Users/koen/Temp/forge/workspace/foo] as project directory? [Y/n] Y
**ERROR** [new-project] WELD-000049 Unable to invoke [method] @PostConstruct public org.jboss.seam.forge.project.facets.builtin.MavenContainer.bootstrapMaven() on org.jboss.seam.forge.project.facets.builtin.MavenContainer@7fa5f230
[no project] workspace $