Confusion about threadlibs?

[walt]

I'm not sure if I'm confused or DragonFly is confused.  After
building world and kernel (HEAD) today, I'm unable to build
pkgsrc/perl5 because miniperl dumps core.

I tried gdb on the coredump:

Reading symbols from /usr/lib/libpthread.so.0...(no debugging symbols
found)...done.
Loaded symbols for /usr/lib/libpthread.so.0
Reading symbols from /usr/pkgsrc/lang/perl5/work/perl-5.8.8/libperl.so...(no
debugging symbols found)...done.
Loaded symbols for /usr/pkgsrc/lang/perl5/work/perl-5.8.8/libperl.so
Reading symbols from /usr/lib/libm.so.3...(no debugging symbols found)...done.
Loaded symbols for /usr/lib/libm.so.3
Reading symbols from /usr/lib/libcrypt.so.3...
(no debugging symbols found)...done.
Loaded symbols for /usr/lib/libcrypt.so.3
Symbols already loaded for /usr/lib/libpthread.so.0
Reading symbols from /usr/lib/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /usr/lib/libc.so.6
Reading symbols from /usr/lib/libthread_xu.so.2...(no debugging symbols
found)...done.
Loaded symbols for /usr/lib/libthread_xu.so.2    <========== huh?

Wait just a minute -- what is libthread_xu doing there?  I'm using
libc_r, not xu:

#ls -l /usr/lib/*thread*
       8 Dec 28 16:18 libpthread.a@ -> libc_r.a
    2940 Jan 16 09:07 libpthread.so
       9 Dec 28 16:17 libpthread.so.0@ -> libc_r.so
 606946 Jan 16 09:07 libthread_xu.a
     17 Jan 16 09:07 libthread_xu.so@ -> libthread_xu.so.2
  61252 Jan 16 09:07 libthread_xu.so.2

There is a new gdb in the mix today, also.  Too many variables
for me.

Anyone else tried building pkgsrc/perl5 on today's HEAD?