Building matplotlib 0.99.1.1: cannot find -ltk8.5

Hi,

I'm having trouble building matplotlib 0.99.1.1 (transcript below).

I'm using copies of Python (2.5.1) and Tcl/Tk (8.5.5) that I have
built myself, and that are apparently working fine. Previously, I was
using this exact procedure to build 0.91.4 without any problems.

Any suggestions would be greatly appreciated - thanks!

Chris

$ cd matplotlib-0.99.1.1
$ env PREFIX=/a/b/ LD_LIBRARY_PATH=/a/b/lib /a/b/bin/python setup.py build

···

============================================================================
BUILDING MATPLOTLIB
            matplotlib: 0.99.1.1
                python: 2.5.1 (r251:54863, Feb 5 2009, 13:11:08) [GCC
                        4.1.2 20071124 (Red Hat 4.1.2-42)]
              platform: linux2

REQUIRED DEPENDENCIES
                 numpy: 1.2.1
             freetype2: 9.10.3

OPTIONAL BACKEND DEPENDENCIES
                libpng: 1.2.10
               Tkinter: Tkinter: 50704, Tk: 8.5, Tcl: 8.5
                  Gtk+: no
                        * Building for Gtk+ requires pygtk; you must be able
                        * to "import gtk" in your build/install environment
       Mac OS X native: no
                    Qt: no
                   Qt4: no
                 Cairo: no

OPTIONAL DATE/TIMEZONE DEPENDENCIES
              datetime: present, version unknown
              dateutil: matplotlib will provide
                  pytz: matplotlib will provide
adding pytz

OPTIONAL USETEX DEPENDENCIES
                dvipng: 1.5
           ghostscript: 8.15.2
                 latex: 3.141592
               pdftops: 3.00

[Edit setup.cfg to suppress the above messages]

pymods ['pylab']
packages ['matplotlib', 'matplotlib.backends', 'matplotlib.projections',
'mpl_toolkits', 'mpl_toolkits.mplot3d', 'mpl_too\
lkits.axes_grid', 'matplotlib.sphinxext', 'matplotlib.numerix',
'matplotlib.numerix.mlab', 'matplotlib.numerix.ma', 'matp\
lotlib.numerix.linear_algebra', 'matplotlib.numerix.random_array',
'matplotlib.numerix.fft', 'matplotlib.delaunay', 'pytz\
', 'dateutil', 'dateutil/zoneinfo']
running build
running build_py
copying lib/matplotlib/mpl-data/matplotlibrc ->
build/lib.linux-i686-2.5/matplotlib/mpl-data
copying lib/matplotlib/mpl-data/matplotlib.conf ->
build/lib.linux-i686-2.5/matplotlib/mpl-data
running build_ext
building 'matplotlib.backends._tkagg' extension
g++ -pthread -shared build/temp.linux-i686-2.5/src/agg_py_transforms.o
build/temp.linux-i686-2.5/src/_tkagg.o build/temp.\
linux-i686-2.5/CXX/cxx_extensions.o build/temp.linux-i686-2.5/CXX/cxxsupport.o
build/temp.linux-i686-2.5/CXX/IndirectPyth\
onInterface.o build/temp.linux-i686-2.5/CXX/cxxextensions.o -L/usr/lib
-L/usr/lib -L/usr/local/lib -L/usr/lib -L/usr/lib6\
4 -L/usr/local/lib -L/usr/lib -L/usr/lib64 -ltk8.5 -ltcl8.5 -lstdc++ -lm
-lfreetype -lz -lstdc++ -lm -o build/lib.linux-i\
686-2.5/matplotlib/backends/_tkagg.so
/usr/bin/ld: cannot find -ltk8.5
collect2: ld returned 1 exit status
error: command 'g++' failed with exit status 1
make: *** [matplotlib] Error 1

$ ls /a/b/lib/*tk*
lib/libtk8.5.so lib/libtkstub8.5.a lib/tkConfig.sh
...