how to turn on tracing

[tziem]

I am having a problem with the 'make test' procedure in DBD-Oracle-1.08.
It seems that one of the test (t/long) hangs after the 20th sub-test.
This only happens against 8.1.6 databases in my environment.
All other database targets (7.3.4, 8.1.5) work fine.
I would like to trace the cause of this.
How do I turn on tracing for the 'make test' procedures?