[ https://jira.codehaus.org/browse/MNG-5613?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=346075#comment-346075 ]
Sébastian Le Merdy commented on MNG-5613: ----------------------------------------- I've followed [this guide|http://maven.apache.org/guides/development/guide-m2-development.html#Dont_forget_tests] to run the integration tests. Result was ok (but took a lot of time :)) > NPE error when building a reactor with duplicated artifacts > ----------------------------------------------------------- > > Key: MNG-5613 > URL: https://jira.codehaus.org/browse/MNG-5613 > Project: Maven 2 & 3 > Issue Type: Bug > Affects Versions: 3.2.1 > Reporter: Dominique Broeglin > Attachments: foo.zip > > > Using v3.2.1 when building a malformed project containing a duplicated > groupId:artifactId I got this rather unhelpful error: > {code} > [ERROR] Internal error: java.lang.NullPointerException -> [Help 1] > org.apache.maven.InternalErrorException: Internal error: > java.lang.NullPointerException > at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:167) > at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584) > at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213) > at org.apache.maven.cli.MavenCli.main(MavenCli.java:157) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:601) > at > org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) > at > org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) > at > org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) > at > org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) > Caused by: java.lang.NullPointerException > at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:270) > at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155) > ... 11 more > {code} > The more helpful error should have been: > {code} > org.apache.maven.project.DuplicateProjectException: Project > 'com.foo.bar:foo-bar:2.15.0' is duplicated in the reactor > at org.apache.maven.project.ProjectSorter.<init>(ProjectSorter.java:93) > at > org.apache.maven.DefaultProjectDependencyGraph.<init>(DefaultProjectDependencyGraph.java:53) > at > org.apache.maven.DefaultMaven.createProjectDependencyGraph(DefaultMaven.java:819) > at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:268) > at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:155) > at org.apache.maven.cli.MavenCli.execute(MavenCli.java:584) > at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:213) > at org.apache.maven.cli.MavenCli.main(MavenCli.java:157) > at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) > at > sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) > at > sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) > at java.lang.reflect.Method.invoke(Method.java:601) > at > org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) > at > org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) > at > org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) > at > org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) > {code} -- This message was sent by Atlassian JIRA (v6.1.6#6162)