Do you have the errai-tools.jar in your classpath?
I was trying to run monitor from within the eclipse but with no luck. I have errai-tools.jar in the ear/lib folder. So I have put at the end of the jboss run.conf following lines :
#Run errai monitor JAVA_OPTS="$JAVA_OPTS -Derrai.tools.bus_monitor_attach=true"
Now console starts every time when I start jboss. This of course works when you use development mode with noserver flag.
Looks like I got stuck between m2eclipse and jboss. :S Although I updated my pom for the dependency and it added it to my classpath, my MANIFEST.MF file did not have the errai-tools reference. Fixed that and now I see the monitor pop up!
Thanks for the tip! However, you can also pass that VM argument via the launch configuration dialog box under VM Arguments. I have JBoss Tools for Eclipse installed and double clicking on my JBoss server opens up a JBoss Configuration page. That has the launch configuration option in it.