maven nullPointer on vaadin-archetype-clean

If a proper maven project, this should not fail:

svn checkout http://dev.vaadin.com/svn/integration/maven/archetypes/MavenArchetype
cd MavenArchetype
mvn compile

[INFO]
Scanning for projects…
[WARNING]

[WARNING]
Some problems were encountered while building the effective model for com.vaadin:vaadin-archetype-sample:maven-arc
hetype:1.6.1
[WARNING]
‘build.plugins.plugin.version’ for org.apache.maven.plugins:maven-gpg-plugin is missing. @ line 110, column 15
[WARNING]

[WARNING]
It is highly recommended to fix these problems because they threaten the stability of your build.
[WARNING]

[WARNING]
For this reason, future Maven versions might no longer support building such malformed projects.
[WARNING]

[INFO]

[INFO]

[INFO]
Building Vaadin Application Archetype 1.6.1
[INFO]

[INFO]

[INFO]
— properties-maven-plugin:1.0-alpha-2:read-project-properties (default) @ vaadin-archetype-sample —
[INFO]

[INFO]
BUILD FAILURE
[INFO]

[INFO]
Total time: 0.925s
[INFO]
Finished at: Fri Nov 04 11:33:38 PDT 2011
[INFO]
Final Memory: 4M/81M
[INFO]

[ERROR]
Failed to execute goal org.codehaus.mojo:properties-maven-plugin:1.0-alpha-2:read-project-properties (default) on pr
oject vaadin-archetype-sample: Execution default of goal org.codehaus.mojo:properties-maven-plugin:1.0-alpha-2:read-project-
properties failed. NullPointerException → [Help 1]

[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/PluginExecutionException