bug report: class "org.hamcrest.Matchers"'s signer information does not match

[huangshiyou]

Bug happens when testing stormpot.MCRPreciseLeakDetectorTest

java.lang.SecurityException: class "org.hamcrest.Matchers"'s signer information does not match signer information of other classes in the same package
	at java.lang.ClassLoader.checkCerts(ClassLoader.java:898)
	at java.lang.ClassLoader.preDefineClass(ClassLoader.java:668)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:761)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:467)
	at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:368)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:362)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:361)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	at stormpot.MCRPreciseLeakDetectorTest.mustHandleManyAddedReplacedAndRemovedObjects(MCRPreciseLeakDetectorTest.java:63)
	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:498)
	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
	at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:76)
	at edu.tamu.aser.exploration.JUnit4MCRRunner.access$2(JUnit4MCRRunner.java:1)
	at edu.tamu.aser.exploration.JUnit4MCRRunner$1.run(JUnit4MCRRunner.java:76)

It seems that hamcrest doesn't work well with jUnit. I tried some suggestions online, but none of them worked.