I agree entirely with your assertions; however, eventually I (or, more importantly, my customers, and for that matter, the perl community at large) will need to debug an app in a threaded environment, if only as a unit testing exersize. (Thread::Apartment makes that need more critical, tho it does provide an i/f to transparently revert to single-threaded mode) The current perl debuggers are simply not useable for that scenario.

I'm working on a solution (working title Devel::Nimbus) similar to ptkdb, but simplified to a notebook with a page for each thread/process, and operating via a sockets i/f to a hacked perl5db. Hopefully it will be sufficient to deal with the issues, and portable enough to be generally useful.