[MNG-4472] [regression] Circular self-referential POM causes network access

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0-alpha-4
• Fix Version/s: 3.0-alpha-6
• Component/s: Reactor and Workspace
• Assignee: Benjamin Bentmann
• Reporter: Paul Benedict
• Created: 27/Nov/09 20:40
• Updated: 07/Apr/15 19:22
• Resolved: 28/Nov/09 10:07

Description

If I were to specify a project with itself as a parent, Maven 2.2.1 gives this response:

[INFO] Scanning for projects...
[INFO] ------------------------------------------------------------------------
[ERROR] FATAL ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Error building POM (may not be this project's POM).


Project ID: org.apache.maven.its.mng:test

Reason: Parent element is a duplicate of the current project  for project org.apache.maven.its.mng:test


[INFO] ------------------------------------------------------------------------
[INFO] Trace
org.apache.maven.reactor.MavenExecutionException: Parent element is a duplicate of the current project  for project org.apache.maven.its.mng:test
        at org.apache.maven.DefaultMaven.getProjects(DefaultMaven.java:404)
        at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:272)
        at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
        at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
        at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
        at java.lang.reflect.Method.invoke(Method.java:597)
        at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
        at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
        at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
        at org.codehaus.classworlds.Launcher.main(Launcher.java:375)
Caused by: org.apache.maven.project.ProjectBuildingException: Parent element is a duplicate of the current project  for project org.apache.maven.its.mng:test

Maven 3 doesn't detect this circularity immediately; it tries to download the parent by going through my remote repositories. The end result is still a failure since it can't find itself, but it's a regression since the network is accessed for this use case.

[INFO] Scanning for projects...
Downloading: http://repo1.maven.org/maven2/org/apache/maven/its/mng/test/0.1/test-0.1.pom
[ERROR] The build could not read 1 project -> [Help 1]
[ERROR]   The project org.apache.maven.its.mng:test:0.1 (D:\patches\MNG-4472\pom.xml) has 2 errors
[ERROR]     The parent element cannot have the same ID as the project.
[ERROR]     Non-resolvable parent POM org.apache.maven.its.mng:test:0.1 for org.apache.maven.its.mng:test:0.1: Failed to resolve POM for org.apache.maven.its.mng:test:0.1 due to Missing:
----------
1) org.apache.maven.its.mng:test:pom:0.1
----------
1 required artifact is missing.

for artifact:
  org.apache.maven.its.mng:test:pom:0.1

from the specified remote repositories:
  central (http://repo1.maven.org/maven2, releases=true, snapshots=false)
    -> [Help 2]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/ProjectBuildingException
[ERROR] [Help 2] http://cwiki.apache.org/confluence/display/MAVEN/UnresolvableModelException