glib2 Error with pkgsrc-2006Q3 on Slackware 10.2

[Dave Vollenweider <metaridley%mchsi.com@localhost>]

I keep getting the following error when trying to compile glib2 on Slackware 
Linux 10.2:

/bin/sh ../libtool --mode=link gcc  -O2 -I/usr/include -Wall  -L/usr/lib 
-Wl,-R/usr/lib -Wl,-R/usr/pkg/lib -o libgthread-2.0.la
-rpath /usr/pkg/lib  -version-info 1200:3:1200 -export-dynamic   
gthread-impl.lo  -lpthreads ../glib/libglib-2.0.la -lrt
gcc -shared  .libs/gthread-impl.o  -Wl,--rpath 
-Wl,/usr/pkgsrc/devel/glib2/work/glib-2.12.3/glib/.libs -lpthreads 
../glib/.libs/libglib-2.0.so -L/usr/pkgsrc/devel/glib2/work/.buildlink/lib -lrt 
 -Wl,-R/usr/pkg/lib -Wl,-soname -Wl,libgthread-2.0.so.0 -o 
.libs/libgthread-2.0.so.0.1200.3
/usr/lib/gcc-lib/i486-slackware-linux/3.3.6/../../../../i486-slackware-linux/bin/ld:
 cannot find -lpthreads
collect2: ld returned 1 exit status
make[2]: *** [libgthread-2.0.la] Error 1
make[2]: Leaving directory `/usr/pkgsrc/devel/glib2/work/glib-2.12.3/gthread'
make[1]: *** [all-recursive] Error 1
make[1]: Leaving directory `/usr/pkgsrc/devel/glib2/work/glib-2.12.3'
make: *** [all] Error 2
*** Error code 2

Stop.
bmake: stopped in /usr/pkgsrc/devel/glib2
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/devel/glib2

Also, before this happened, I noticed this warning from gcc appearing 
repeatedly:

gcc: unrecognized option `-pthreads'

Now, I did recently switch Linux kernels, from 2.4.31 to 2.6.17.13, and I'm 
wondering if that has anything to do with this error.

I also just learned that Slackware 11.0 came out, and I shall try upgrading.  
However, I thought bringing it up early would be best.

Anyone know if there's anything I can do about this short of modifying the 
source?  I did look in the mailing list archives and it seems that this problem 
has come up with other programs in the past on various OSs and had something to 
do with libtool-base.  I recompiled and reinstalled that package, but to no 
avail.  I also tried installing devel/pth but pkgsrc doesn't seem to use it if 
a native pthread implementation is available.

Any ideas?

- Dave V.