ruby-1.8.4
CFLAGS="-O0 +DD64 -g -D_XOPEN_SOURCE -D_XOPEN_SOURCE_EXTENDED=1" ./configure --prefix=/usr
--enable-wide-getaddrinfo

I've compiled ruby in a variety of ways and all hit the same problem with the following test program:

#!/usr/bin/ruby -w
thread = Thread.new {
    sleep 1
    print "Hi\n"
}
print "Waiting\n"
thread.join
print "Done\n"

# ./threadtest.rb
Waiting
./threadtest.rb:3: [BUG] Segmentation fault
ruby 1.8.4 (2005-12-24) [ia64-hpux11.23]

Abort(coredump)

Stack:

#0  0xc000000000316b70:0 in kill+0x30 () from /usr/lib/hpux64/libc.so.1
#1  0xc00000000023b2d0:0 in raise+0x30 () from /usr/lib/hpux64/libc.so.1
#2  0xc0000000002d8270:0 in abort+0x190 () from /usr/lib/hpux64/libc.so.1
#3  0x40000000004180c0:0 in rb_bug (
    fmt=0x4000000000069930 "Segmentation fault") at error.c:214
#4  0x400000000031af90:0 in sigsegv (sig=11) at signal.c:447
#5  <signal handler called>
#6  0x40000000000f74b0:0 in rb_thread_schedule () at eval.c:10612

I'm willing to help work on this but I don't know anything about this area of the code.