Thanks for the responses. I went with the following:
In the following modules, I added 'threads' as a
prerequisite:
threads::shared
Thread::Queue
Thread::Semaphore
Thread::Cancel
Thread::Suspend
In the Makefile.PL for 'threads', I used (per Dave's
suggestion):
use Config;
BEGIN {
die("OS unsupported: ERROR: This Perl not built to support threads\n")
if (! $Config{'useithreads'});
}
This should result in NA's for any attempts to install
'threads' on non-threaded Perls, and no reports at all for
the other modules because their 'threads' prerequiste is not
met.