unable to compile widgetset on mac & maven

Hi,

I have just created a project with maven following the instructions in the
wiki
but I am unable to compile the widgetset.

I’m on a mac (snow leopard), maven 3

mvn -version
Apache Maven 3.0.4 (r1232337; 2012-01-17 09:44:56+0100)
Maven home: /usr/share/maven
Java version: 1.7.0_55, vendor: Oracle Corporation
Java home: /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "mac os x", version: "10.6.8", arch: "x86_64", family: "mac"

I can compile and update-widgetset but I can’t compile widgetset :

-----------------------------------------------------------------------
[INFO]
 BUILD FAILURE
[INFO]
 ------------------------------------------------------------------------
[INFO]
 Total time: 10.743s
[INFO]
 Finished at: Mon Sep 29 18:13:24 CEST 2014
[INFO]
 Final Memory: 13M/182M
[INFO]
 ------------------------------------------------------------------------
[ERROR]
 Failed to execute goal com.vaadin:vaadin-maven-plugin:7.1.8:compile (default-cli) on project multilevelcombo: Command [[
[ERROR]
 /bin/sh -c /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home/jre/bin/java -Xmx512M -Xss1024k -classpath /Users/marco/devel/multilevelcombo/target/classes:/Users/marco/devel/multilevelcombo/src/main/java:/Users/marco/devel/multilevelcombo/src/main/resources:/Users/marco/.m2/repository/com/vaadin/vaadin-server/7.1.8/vaadin-server-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-shared/7.1.8/vaadin-shared-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-shared-deps/1.0.2/vaadin-shared-deps-1.0.2.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-theme-compiler/7.1.8/vaadin-theme-compiler-7.1.8.jar:/Users/marco/.m2/repository/org/apache/commons/commons-jexl/2.1.1/commons-jexl-2.1.1.jar:/Users/marco/.m2/repository/commons-cli/commons-cli/1.2/commons-cli-1.2.jar:/Users/marco/.m2/repository/org/jsoup/jsoup/1.6.3/jsoup-1.6.3.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client-compiler/7.1.8/vaadin-client-compiler-7.1.8.jar:/Users/marco/.m2/repository/commons-collections/commons-collections/3.1/commons-collections-3.1.jar:/Users/marco/.m2/repository/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar:/Users/marco/.m2/repository/ant/ant/1.6.5/ant-1.6.5.jar:/Users/marco/.m2/repository/net/sourceforge/cssparser/cssparser/0.9.5/cssparser-0.9.5.jar:/Users/marco/.m2/repository/ant/ant-launcher/1.6.5/ant-launcher-1.6.5.jar:/Users/marco/.m2/repository/org/mortbay/jetty/jetty/6.1.11/jetty-6.1.11.jar:/Users/marco/.m2/repository/org/mortbay/jetty/servlet-api-2.5/6.1.11/servlet-api-2.5-6.1.11.jar:/Users/marco/.m2/repository/org/mortbay/jetty/jetty-util/6.1.11/jetty-util-6.1.11.jar:/Users/marco/.m2/repository/org/jdesktop/swing-worker/1.1/swing-worker-1.1.jar:/Users/marco/.m2/repository/commons-codec/commons-codec/1.3/commons-codec-1.3.jar:/Users/marco/.m2/repository/commons-io/commons-io/2.2/commons-io-2.2.jar:/Users/marco/.m2/repository/commons-lang/commons-lang/2.6/commons-lang-2.6.jar:/Users/marco/.m2/repository/org/apache/james/apache-mime4j/0.6/apache-mime4j-0.6.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client-compiler-deps/1.0.2/vaadin-client-compiler-deps-1.0.2.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client/7.1.8/vaadin-client-7.1.8.jar:/Users/marco/.m2/repository/org/w3c/css/sac/1.3/sac-1.3.jar:/Users/marco/.m2/repository/javax/validation/validation-api/1.0.0.GA/validation-api-1.0.0.GA.jar:/Users/marco/.m2/repository/javax/validation/validation-api/1.0.0.GA/validation-api-1.0.0.GA-sources.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-push/7.1.8/vaadin-push-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-runtime/1.0.14.vaadin4/atmosphere-runtime-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-compat-jbossweb/1.0.14.vaadin4/atmosphere-compat-jbossweb-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-compat-tomcat/1.0.14.vaadin4/atmosphere-compat-tomcat-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-compat-tomcat7/1.0.14.vaadin4/atmosphere-compat-tomcat7-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/slf4j/vaadin-slf4j-jdk14/1.6.1/vaadin-slf4j-jdk14-1.6.1.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-themes/7.1.8/vaadin-themes-7.1.8.jar:/Users/marco/.m2/repository/javax/servlet/javax.servlet-api/3.0.1/javax.servlet-api-3.0.1.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client/7.1.8/vaadin-client-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client-compiler/7.1.8/vaadin-client-compiler-7.1.8.jar com.google.gwt.dev.Compiler -logLevel INFO -style OBF -war /Users/marco/devel/multilevelcombo/src/main/webapp/VAADIN/widgetsets -localWorkers 2 -strict -XfragmentCount -1 -extra /Users/marco/devel/multilevelcombo/target/extra -compileReport -gen /Users/marco/devel/multilevelcombo/target/.generated com.randbee.AppWidgetSet
[ERROR]
 ]] failed with status 133
[ERROR]
 -> [Help 1]

I have already tried adding vaadin-client-compiler dependency and removing vaadin-client-compiled but nothing changes.
If I try the command that returns the error I get an error on usage :

/bin/sh -c /Library/Java/JavaVirtualMachines/jdk1.7.0_55.jdk/Contents/Home/jre/bin/java -Xmx512M -Xss1024k -classpath /Users/marco/devel/multilevelcombo/target/classes:/Users/marco/devel/multilevelcombo/src/main/java:/Users/marco/devel/multilevelcombo/src/main/resources:/Users/marco/.m2/repository/com/vaadin/vaadin-server/7.1.8/vaadin-server-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-shared/7.1.8/vaadin-shared-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-shared-deps/1.0.2/vaadin-shared-deps-1.0.2.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-theme-compiler/7.1.8/vaadin-theme-compiler-7.1.8.jar:/Users/marco/.m2/repository/org/apache/commons/commons-jexl/2.1.1/commons-jexl-2.1.1.jar:/Users/marco/.m2/repository/commons-cli/commons-cli/1.2/commons-cli-1.2.jar:/Users/marco/.m2/repository/org/jsoup/jsoup/1.6.3/jsoup-1.6.3.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client-compiler/7.1.8/vaadin-client-compiler-7.1.8.jar:/Users/marco/.m2/repository/commons-collections/commons-collections/3.1/commons-collections-3.1.jar:/Users/marco/.m2/repository/commons-logging/commons-logging/1.1.1/commons-logging-1.1.1.jar:/Users/marco/.m2/repository/ant/ant/1.6.5/ant-1.6.5.jar:/Users/marco/.m2/repository/net/sourceforge/cssparser/cssparser/0.9.5/cssparser-0.9.5.jar:/Users/marco/.m2/repository/ant/ant-launcher/1.6.5/ant-launcher-1.6.5.jar:/Users/marco/.m2/repository/org/mortbay/jetty/jetty/6.1.11/jetty-6.1.11.jar:/Users/marco/.m2/repository/org/mortbay/jetty/servlet-api-2.5/6.1.11/servlet-api-2.5-6.1.11.jar:/Users/marco/.m2/repository/org/mortbay/jetty/jetty-util/6.1.11/jetty-util-6.1.11.jar:/Users/marco/.m2/repository/org/jdesktop/swing-worker/1.1/swing-worker-1.1.jar:/Users/marco/.m2/repository/commons-codec/commons-codec/1.3/commons-codec-1.3.jar:/Users/marco/.m2/repository/commons-io/commons-io/2.2/commons-io-2.2.jar:/Users/marco/.m2/repository/commons-lang/commons-lang/2.6/commons-lang-2.6.jar:/Users/marco/.m2/repository/org/apache/james/apache-mime4j/0.6/apache-mime4j-0.6.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client-compiler-deps/1.0.2/vaadin-client-compiler-deps-1.0.2.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client/7.1.8/vaadin-client-7.1.8.jar:/Users/marco/.m2/repository/org/w3c/css/sac/1.3/sac-1.3.jar:/Users/marco/.m2/repository/javax/validation/validation-api/1.0.0.GA/validation-api-1.0.0.GA.jar:/Users/marco/.m2/repository/javax/validation/validation-api/1.0.0.GA/validation-api-1.0.0.GA-sources.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-push/7.1.8/vaadin-push-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-runtime/1.0.14.vaadin4/atmosphere-runtime-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-compat-jbossweb/1.0.14.vaadin4/atmosphere-compat-jbossweb-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-compat-tomcat/1.0.14.vaadin4/atmosphere-compat-tomcat-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/atmosphere/atmosphere-compat-tomcat7/1.0.14.vaadin4/atmosphere-compat-tomcat7-1.0.14.vaadin4.jar:/Users/marco/.m2/repository/com/vaadin/external/slf4j/vaadin-slf4j-jdk14/1.6.1/vaadin-slf4j-jdk14-1.6.1.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-themes/7.1.8/vaadin-themes-7.1.8.jar:/Users/marco/.m2/repository/javax/servlet/javax.servlet-api/3.0.1/javax.servlet-api-3.0.1.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client/7.1.8/vaadin-client-7.1.8.jar:/Users/marco/.m2/repository/com/vaadin/vaadin-client-compiler/7.1.8/vaadin-client-compiler-7.1.8.jar com.google.gwt.dev.Compiler -logLevel INFO -style OBF -war /Users/marco/devel/multilevelcombo/src/main/webapp/VAADIN/widgetsets -localWorkers 2 -strict -XfragmentCount -1 -extra /Users/marco/devel/multilevelcombo/target/extra -compileReport -gen /Users/marco/devel/multilevelcombo/target/.generated com.randbee.AppWidgetSet
Usage: java [-options]
 class [args...]

(to execute a class)
or java [-options]
 -jar jarfile [args...]

(to execute a jar file)
where options include:
-d32 use a 32-bit data model if available
-d64 use a 64-bit data model if available
-server to select the "server" VM
The default VM is server,
because you are running on a server-class machine.


-cp <class search path of directories and zip/jar files>
-classpath <class search path of directories and zip/jar files>
A : separated list of directories, JAR archives,
and ZIP archives to search for class files.
-D<name>=<value>
set a system property
-verbose:[class|gc|jni]

enable verbose output
-version print product version and exit
-version:<value>
require the specified version to run
-showversion print product version and continue
-jre-restrict-search | -no-jre-restrict-search
include/exclude user private JREs in the version search
-? -help print this help message
-X print help on non-standard options
-ea[:<packagename>...|:<classname>]

-enableassertions[:<packagename>...|:<classname>]

enable assertions with specified granularity
-da[:<packagename>...|:<classname>]

-disableassertions[:<packagename>...|:<classname>]

disable assertions with specified granularity
-esa | -enablesystemassertions
enable system assertions
-dsa | -disablesystemassertions
disable system assertions
-agentlib:<libname>
load native agent library <libname>, e.g. -agentlib:hprof
see also, -agentlib:jdwp=help and -agentlib:hprof=help
-agentpath:<pathname>
load native agent library by full pathname
-javaagent:<jarpath>
load Java programming language agent, see java.lang.instrument
-splash:<imagepath>
show splash screen with specified image
See http://www.oracle.com/technetwork/java/javase/documentation/index.html for more details.

No problem on a Linux machine.
Any help would greatly be appreciated.

TIA
Marco