ecj-4.6M7 ant build failure

gistfile1.txt

build.xml:311: The following error occurred while executing this line:
build.xml:347: java.lang.reflect.InvocationTargetException
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.eclipse.jdt.core.JDTCompilerAdapter.execute(JDTCompilerAdapter.java:80)
	at org.apache.tools.ant.taskdefs.Javac.compile(Javac.java:1160)
	at org.apache.tools.ant.taskdefs.Javac.execute(Javac.java:936)
	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
	at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
	at org.apache.tools.ant.Task.perform(Task.java:348)
	at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68)
	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
	at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
	at org.apache.tools.ant.Task.perform(Task.java:348)
	at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:396)
	at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:293)
	at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:497)
	at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
	at org.apache.tools.ant.Task.perform(Task.java:348)
	at org.apache.tools.ant.Target.execute(Target.java:435)
	at org.apache.tools.ant.Target.performTasks(Target.java:456)
	at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1405)
	at org.apache.tools.ant.Project.executeTarget(Project.java:1376)
	at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
	at org.apache.tools.ant.Project.executeTargets(Project.java:1260)
	at org.apache.tools.ant.Main.runBuild(Main.java:853)
	at org.apache.tools.ant.Main.startAnt(Main.java:235)
	at org.apache.tools.ant.launch.Launcher.run(Launcher.java:285)
	at org.apache.tools.ant.launch.Launcher.main(Launcher.java:112)
Caused by: java.lang.NoClassDefFoundError: org/eclipse/jdt/internal/core/INameEnvironmentWithProgress
	at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.createPackage(LookupEnvironment.java:783)
	at org.eclipse.jdt.internal.compiler.lookup.CompilationUnitScope.buildTypeBindings(CompilationUnitScope.java:110)
	at org.eclipse.jdt.internal.compiler.lookup.LookupEnvironment.buildTypeBindings(LookupEnvironment.java:212)
	at org.eclipse.jdt.internal.compiler.Compiler.internalBeginToCompile(Compiler.java:820)
	at org.eclipse.jdt.internal.compiler.Compiler.beginToCompile(Compiler.java:385)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:435)
	at org.eclipse.jdt.internal.compiler.Compiler.compile(Compiler.java:417)
	at org.eclipse.jdt.internal.compiler.batch.Main.performCompilation(Main.java:4180)
	at org.eclipse.jdt.internal.compiler.batch.Main.compile(Main.java:1712)
	... 37 more
Caused by: java.lang.ClassNotFoundException: org.eclipse.jdt.internal.core.INameEnvironmentWithProgress
	at org.apache.tools.ant.AntClassLoader.findClassInComponents(AntClassLoader.java:1388)
	at org.apache.tools.ant.AntClassLoader.findClass(AntClassLoader.java:1337)
	at org.apache.tools.ant.AntClassLoader.loadClass(AntClassLoader.java:1089)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 46 more