Can't use grails-maven-plugin with JDK 7

It looks like the plugin has dependencies to the classes.jar included with JDK6.
This file does not exist anymore in JDK 7.

<profile>
<id>jdk_mac</id>
<activation>
<os>
<family>mac</family>
</os>
</activation>
<dependencies>
<dependency>
<groupId>com.sun</groupId>
<artifactId>tools</artifactId>
<version>1.6</version>
<scope>system</scope>
<systemPath>$

/bundle/Classes/classes.jar</systemPath>
</dependency>
</dependencies>
</profile>

A mvn build throws the following exception:

$ mvn clean install
[INFO] Scanning for projects...
[ERROR] The build could not read 1 project -> [Help 1]
[ERROR]
[ERROR] The project be.ixor:doccle-euui:0.2-SNAPSHOT (/Users/ct/Projects/ixor/doccle/pom.xml) has 2 errors
[ERROR] Unresolveable build extension: Plugin org.grails:grails-maven-plugin:2.1.0 or one of its dependencies could not be resolved: Could not find artifact com.sun:tools:jar:1.6 at specified path /Library/Java/JavaVirtualMachines/jdk1.7.0_07.jdk/Contents/Home/jre/bundle/Classes/classes.jar -> [Help 2]
[ERROR] Unknown packaging: grails-app @ line 9, column 16
[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/PluginResolutionException