Ant

https://blog.mikeski.net/blog_post/30
Ivy “Impossible to Acquire Lock”
Easy way to get IVY to release all locks.
find ~/.ivy -name '*.lck' -exec rm -f {} \;

https://stackoverflow.com/questions/25701740/java-thread-dump-waiting-on-object-monitor-what-is-it-waiting-on
Java thread dump: WAITING (on object monitor) - what is it waiting on?

It's a peculiarity of HotSpot JVM. When dumping a stack, JVM recovers the wait object from the method local variables. This info is available for interpreted methods, but not for compiled native wrappers.

When Object.wait is executed frequently enough, it gets JIT-compiled.
After that there will be no "waiting on" line in a thread dump.

1. Since wait() must be called on a synchronized object, most often the wait object is the last locked object in the stack trace. In your case it is

   - locked <0x00007f98cbebe5d8> (a com.tibco.tibjms.TibjmsxResponse)
   

2. To prevent Object.wait from being JIT-compiled (and thus making wait info always available) use the following JVM option

   -XX:CompileCommand="exclude,java/lang/Object.wait" 
   

https://issues.gradle.org/browse/GRADLE-1723

       :::: ERRORS
               impossible to acquire lock for org.grails#grails-docs;1.3.6

find ~/.gradle/caches/artifacts/ -name "*.lck" 
/home/davide/.gradle/caches/artifacts/asm/asm-util/wharfdata-3.2.kryo.lck

Removing it while a milestone-4 process was hanging, it continued soon with no problems.

https://stackoverflow.com/questions/25039864/specifying-jvm-arguments-in-ant-tasks

You can set ANT_OPTS parameters. For example in Windows

SET ANT_OPTS=-Xmx1024m -XX:MaxPermSize=256m

or just use maxmemory attribute of junit ant task (http://ant.apache.org/manual/Tasks/junit.html):

<junit maxmemory="1024m" ...

<junit printsummary="true" fork="yes" haltonfailure="false" failureproperty="junitsFailed" errorProperty="junitsFailed">
    <jvmarg value="-Xmx1024m"/>
    <jvmarg value="-Duser.timezone=GMT0"/>
</junit>