Debug messages can be generated using an environment variable, JDCNDBG. Turn messages on with:
setenv JDCNDBG 1 (C shell)
export JDCNDBG=1 (Korn shell)
and off with:
setenv JDCNDBG (C shell)
unset JDCNDBG (Korn shell)
The variable can be assigned values 1, 2, 3 .. to give progressively more detailed diagnostics.