Custom Trace in WebSphere Message Broker 7

It happens that standard console, syslog or eventviewer is not enough to understand an error in WebSphere Message Broker. It happened to me recently when implementing ws-security in WMB 7.0.0.1. 
Long story short I faced an CWWSS6521E error with huge stacktrace and funny exception 

com.ibm.wsspi.wssecurity.core.SoapSecurityException: CWWSS6521E: Logowanie nie powiodło się z powodu wyjątku.: javax.security.auth.login.LoginException: caught exception from broker

There was no place in Broker where I could easily look for more details. Even service trace in official debug mode didn't show anything more detailed than this stacktrace. 
My coworker has sent me this link to one of possible reasons but stacktrace was different so I had to be sure before I install additional fixes. 
Here is solution: 

1. Add to execution group additional flag pointing a file: -DtraceSettingsFile=MyTraceSettings.properties 
2. Create file MyTraceSettings.properties with body: com.ibm.ws.wssecurity.*=all=enabled 

This flag will configure trace to store tons of debug information and finally will show more detailed exception in debug:

Found an extranious X509 token - more than configured for PolicySet

For better undestanding those debugs jars responsible for ws-security are: ws-security-impl-1.0-SNAPSHOT.jar or com.ibm.jaxws.thinclient_7.0.0 depending on version of WMB. 

I had upgrade my broker to version 7.0.0.6 and it fixed my errors.