GWT + MVP4g+Ivy: compilation error

I have added the mvp4g jar for project through ivy configuration.It added properly and also mention line in the gwt.xml file for mvp4g.But i am trying to compile the application it gives me following error:

Loading inherited module 'com.mvp4g.Mvp4gModule' [ERROR] Unable to find 'com/mvp4g/Mvp4gModule.gwt.xml' on your classpath; could be a typo, or maybe you forgot to include a classpath entry for source? [ERROR] Line 13: Unexpected exception while processing element 'inherits' com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries) at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:278) at com.google.gwt.dev.cfg.ModuleDefSchema$BodySchema.__inherits_begin(ModuleDefSchema.java:495) at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at com.google.gwt.dev.util.xml.HandlerMethod.invokeBegin(HandlerMethod.java:230) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.startElement(ReflectiveParser.java:294) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:501) at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:179) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1343) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2755) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1205) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:347) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68) at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418) at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:296) at com.google.gwt.dev.cfg.ModuleDefLoader$1.load(ModuleDefLoader.java:198) at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:324) at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:156) at com.google.gwt.dev.Compiler.run(Compiler.java:196) at com.google.gwt.dev.Compiler$1.run(Compiler.java:170) at com.google.gwt.dev.CompileTaskRunner.doRun(CompileTaskRunner.java:88) at com.google.gwt.dev.CompileTaskRunner.runWithAppropriateLogger(CompileTaskRunner.java:82) at com.google.gwt.dev.Compiler.main(Compiler.java:177) [ERROR] Failure while parsing XML com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries) at com.google.gwt.dev.util.xml.DefaultSchema.onHandlerException(DefaultSchema.java:58) at com.google.gwt.dev.util.xml.Schema.onHandlerException(Schema.java:66) at com.google.gwt.dev.util.xml.Schema.onHandlerException(Schema.java:66) at com.google.gwt.dev.util.xml.HandlerMethod.invokeBegin(HandlerMethod.java:240) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.startElement(ReflectiveParser.java:294) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.startElement(AbstractSAXParser.java:501) at com.sun.org.apache.xerces.internal.parsers.AbstractXMLDocumentParser.emptyElement(AbstractXMLDocumentParser.java:179) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanStartElement(XMLDocumentFragmentScannerImpl.java:1343) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl$FragmentContentDriver.next(XMLDocumentFragmentScannerImpl.java:2755) at com.sun.org.apache.xerces.internal.impl.XMLDocumentScannerImpl.next(XMLDocumentScannerImpl.java:648) at com.sun.org.apache.xerces.internal.impl.XMLDocumentFragmentScannerImpl.scanDocument(XMLDocumentFragmentScannerImpl.java:511) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:808) at com.sun.org.apache.xerces.internal.parsers.XML11Configuration.parse(XML11Configuration.java:737) at com.sun.org.apache.xerces.internal.parsers.XMLParser.parse(XMLParser.java:119) at com.sun.org.apache.xerces.internal.parsers.AbstractSAXParser.parse(AbstractSAXParser.java:1205) at com.sun.org.apache.xerces.internal.jaxp.SAXParserImpl$JAXPSAXParser.parse(SAXParserImpl.java:522) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:347) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68) at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418) at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:296) at com.google.gwt.dev.cfg.ModuleDefLoader$1.load(ModuleDefLoader.java:198) at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:324) at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:156) at com.google.gwt.dev.Compiler.run(Compiler.java:196) at com.google.gwt.dev.Compiler$1.run(Compiler.java:170) at com.google.gwt.dev.CompileTaskRunner.doRun(CompileTaskRunner.java:88) at com.google.gwt.dev.CompileTaskRunner.runWithAppropriateLogger(CompileTaskRunner.java:82) at com.google.gwt.dev.Compiler.main(Compiler.java:177) [ERROR] Unexpected error while processing XML com.google.gwt.core.ext.UnableToCompleteException: (see previous log entries) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.parse(ReflectiveParser.java:371) at com.google.gwt.dev.util.xml.ReflectiveParser$Impl.access$200(ReflectiveParser.java:68) at com.google.gwt.dev.util.xml.ReflectiveParser.parse(ReflectiveParser.java:418) at com.google.gwt.dev.cfg.ModuleDefLoader.nestedLoad(ModuleDefLoader.java:296) at com.google.gwt.dev.cfg.ModuleDefLoader$1.load(ModuleDefLoader.java:198) at com.google.gwt.dev.cfg.ModuleDefLoader.doLoadModule(ModuleDefLoader.java:324) at com.google.gwt.dev.cfg.ModuleDefLoader.loadFromClassPath(ModuleDefLoader.java:156) at com.google.gwt.dev.Compiler.run(Compiler.java:196) at com.google.gwt.dev.Compiler$1.run(Compiler.java:170) at com.google.gwt.dev.CompileTaskRunner.doRun(CompileTaskRunner.java:88) at com.google.gwt.dev.CompileTaskRunner.runWithAppropriateLogger(CompileTaskRunner.java:82) at com.google.gwt.dev.Compiler.main(Compiler.java:177)

Please help me on this.

Solution

Analysis

After digging around the project homepage, I've discovered that the missing XML file is actually located inside the jar file:

unzip -t ./Mvp4g_Layout_Part2/war/WEB-INF/lib/mvp4g-1.4.0.jar | grep xml
testing: com/mvp4g/Mvp4gModule.gwt.xml   OK
testing: META-INF/maven/com.googlecode.mvp4g/mvp4g/pom.xml   OK

This means while the may have been downloaded by ivy, it is not present on your compile classpath.

Assumption

You haven't specified how you're using the jar, so I must assuming the above error was thrown by the ANT javac task.

Example

ivy.xml

I'd declare the dependency in ivy and associate it with a compile configuration as follows:

<ivy-module version="2.0">
    <info organisation="com.myspotontheweb" module="demo"/>

    <configurations>
        <conf name="compile" description="Required to compile application"/>
    </configurations>

    <dependencies>
        <dependency org="com.googlecode.mvp4g" name="mvp4g" rev="1.4.0" conf="compile->default"/>
    </dependencies>

</ivy-module>

build.xml

In the ANT file I'd use the ivy cachepath task to create an ivy managed ANT path.

<target name="init">
    <ivy:resolve/>

    <ivy:report todir='${ivy.reports.dir}' graph='false' xml='false'/>

    <ivy:cachepath pathid="compile.path" conf="compile"/>
</target>

This path is then used as normal in the javac task (or any other ANT task that can accept a classpath reference)

<target name="compile" depends="init">
    <javac srcdir="${src.dir}" destdir="${classes.dir}" includeantruntime="false" debug="true" classpathref="compile.path"/>
</target>