The pthread_dbg library provides an implementation of the standard POSIX
threads library debugging facilities.

The NetBSD implementation is based on 1:1 thread model, therefore each
pthread(3) has a kernel thread, called a light-weight process (LWP).

Note that the system private thread interfaces upon which the pthread(3)
library is built are subject to change without notice.  In order to
remain compatible with future NetBSD releases, programs must be linked
against the dynamic version of the thread library.  Statically linked
programs using the POSIX threads framework may not work when run on a
future version of the system.

The pthread_dbg library is designed to be used in debuggers and to
control and introspect the NetBSD implementation of the POSIX threads.
Software may use native LWP threads without pthread(3) layer, in that
case pthread_dbg cannot be used.