Threads-related(?) application hangs with recent -CURRENT

Hi there,

After upgrading from August 10's -CURRENT to yesterday's, I've noticed
that Mozilla, Psi, and other apps stopped working, that is, after
process is spawned, it shortly stops doing anything, and is unkillable.
Editing /etc/libmap.conf to use libc_r instead helps.

After trying to upgrade Python, ./configure hangs likewise, on this mere
conftest.c program:

#include <pthread.h>

void* routine(void* p){return NULL;}

int main(){
  pthread_t p;
  if(pthread_create(&p,NULL,routine,NULL)!=0)
    return 1;
  (void)pthread_detach(p);
  return 0;
}

Was there something committed to pthread code that can cause this
misbehavior?  What information can I provide to possibly help
investigating this issue?

Thanks!

./danfe