Grails IncompatibleClassChangeError

Question

I deploy a war made with "grails war" to a jetty server.

As far as I can determine, Grails builds with Sun JDK 1.6.0_17-b04 and jetty runs on Sun JDK 1.6.0.16 (both on linux).

2010-08-18 07:33:47.018:WARN::Nested in org.springframework.beans.factory.access.BootstrapException: Error executing bootstraps; nested exception is org.codehaus.groovy.runtime.InvokerInvocationException:     
java.lang.IncompatibleClassChangeError: the number of constructors during runtime and compile time for java.lang.ClassLoader do not match. Expected 3 but got 2:
java.lang.IncompatibleClassChangeError: the number of constructors during runtime and compile time for java.lang.ClassLoader do not match. Expected 3 but got 2
at grails.plugin.scopedproxy.AlwaysReloadableSmartClassLoader.<init>(AlwaysReloadableSmartClassLoader.groovy:28)
at grails.plugin.scopedproxy.ScopedProxyUtils.wrapInSmartClassLoader(ScopedProxyUtils.groovy:154)

How can this problem be solved or debugged further?

Answer 1

Restart Jetty?

Its trying to reload the code following your changes and it thinks the code has changed more than it can handle :(

Answer 2

Run grails clean before you run grails war.