debugging coprocessors in Netbeans

[Pavel Hančar]

 Hello,
please, do you have a tip for debugging of coprocessors in Netbeans?
I've got stuck on the line
table.coprocessorExec{
and I am not able to trace the coprocessor. I tried to run HBase with
HBASE_OPTS="-Xrunjdwp:transport=dt_socket,address=4530,server=y,suspend=n"
Then I tried Debug > Attach Debugger

In Debugger console I have this:
Attaching to golem:4530
User program running

But all the buttons like "Step Over" are inactive and I can't see any
variable, but: "No variables to display, because there is no current
thread."

What to do?
 Thanks.