Need help widgetSet compilation

When trying to compile the widgetSet of my project with the Eclipse Plugin, I get the following message and couldn’t run my application. Did anybody have the same issue?

Executing compiler with command line: […]

INFO: Widgetsets found from classpath:
com.example.preproject.widgetset.PreprojectWidgetset in file://C/Users/Info/WorkspaceSBE/preProject/src
com.vaadin.DefaultWidgetSet in jar:file:C:/Users/Info/.ivy2/cache/com.vaadin/vaadin-client/jars/vaadin-client-7.1.0.jar!/
Addon styles found from classpath:

10 juil. 2013 10:58:16 com.vaadin.server.widgetsetutils.ClassPathExplorer getAvailableWidgetSetsAndStylesheets
INFO: Search took 18ms
Done.
Starting GWT compiler
Unknown argument: -out
Google Web Toolkit 7.1.0
Compiler [-logLevel level]
[-workDir dir]
[-compileReport]
[-XdisableCastChecking]
[-XdisableClassMetadata]
[-draftCompile]
[-ea]
[-XenableClosureCompiler]
[-XfragmentCount numFragments]
[-XfragmentMerge numFragments]
[-gen dir]
[-optimize level]
[-style style]
[-strict]
[-validateOnly]
[-localWorkers count]
[-war dir]
[-deploy dir]
[-extra dir]
module

where
-logLevel The level of logging detail: ERROR, WARN, INFO, TRACE, DEBUG, SPAM, or ALL
-workDir The compiler’s working directory for internal use (must be writeable; defaults to a system temp dir)
-compileReport Create a compile report that tells the Story of Your Compile
-XdisableCastChecking EXPERIMENTAL: Disables run-time checking of cast operations
-XdisableClassMetadata EXPERIMENTAL: Disables some java.lang.Class methods (e.g. getName())
-draftCompile Enable faster, but less-optimized, compilations
-ea Debugging: causes the compiled output to check assert statements
-XenableClosureCompiler EXPERIMENTAL: Enables Closure Compiler optimizations
-XfragmentCount EXPERIMENTAL: Limits of number of fragments using a code splitter that merges split points.
-XfragmentMerge DEPRECATED (use -XfragmentCount instead): Enables Fragment merging code splitter.
-gen Debugging: causes normally-transient generated types to be saved in the specified directory
-optimize Sets the optimization level used by the compiler. 0=none 9=maximum.
-style Script output style: OBF[USCATED]
, PRETTY, or DETAILED (defaults to OBF)
-strict Only succeed if no input files have errors
-validateOnly Validate all source code, but do not compile
-localWorkers The number of local workers to use when compiling permutations
-war The directory into which deployable output files will be written (defaults to ‘war’)
-deploy The directory into which deployable but not servable output files will be written (defaults to ‘WEB-INF/deploy’ under the -war directory/jar, and may be the same as the -extra directory/jar)
-extra The directory into which extra files, not intended for deployment, will be written
and
module Specifies the name(s) of the module(s) to compile
Widgetset compilation failed

And when i run my application i have that error → com.vaadin.server.VaadinServlet serveStaticResourcesInVAADININFO: Requested resource
[/VAADIN/widgetsets/com.example.preproject.widgetset.PreprojectWidgetset/com.example.preproject.widgetset.PreprojectWidgetset.nocache.js] not found from filesystem or through class loader. Add widgetset and/or theme JAR to your classpath or add files to WebContent/VAADIN folder.

Finally i solved my problem.

Right click on the WidgetSet.gwt.xml file , run as, compile as gwt application. A folder is generate on webContent, place it in VAADIN/widgetsets (create it if not exists)