MesaLib build failure

[Hisashi T Fujinaka <htodd%twofifty.com@localhost>]

With current sources, MesaLib doesn't appear to build. option.mk doesn't
make that much sense to me. There's no dependency on libdrm but it
appears to find an old version somewhere once I comment out the first
error (in the log I'm attaching).

--
Hisashi T Fujinaka - htodd%twofifty.com@localhost
BSEE(6/86) + BSChem(3/95) + BAEnglish(8/95) + MSCS(8/03) + $2.50 = latte

===> Cleaning for MesaLib-7.11.2
===> Cleaning for MesaLib-7.11.2
=> Bootstrap dependency digest>=20010302: found digest-20121220
=> Checksum SHA1 OK for Mesa-7.11.2/MesaGLUT-7.11.2.tar.bz2
=> Checksum RMD160 OK for Mesa-7.11.2/MesaGLUT-7.11.2.tar.bz2
=> Checksum SHA1 OK for Mesa-7.11.2/MesaLib-7.11.2.tar.bz2
=> Checksum RMD160 OK for Mesa-7.11.2/MesaLib-7.11.2.tar.bz2
===> Installing dependencies for MesaLib-7.11.2
==========================================================================
The following variables will affect the build process of this package,
MesaLib-7.11.2.  Their current value is shown below:

        * PYTHON_VERSION_DEFAULT = 27

Based on these variables, the following variables have been set:

        * PYPACKAGE = python27

You may want to abort the process now with CTRL-C and change their value
before continuing.  Be sure to run `/usr/bin/make clean' after
the changes.
==========================================================================
=> Tool dependency automake>=1.9: found automake-1.13.2
=> Tool dependency autoconf>=2.58: found autoconf-2.69nb1
=> Tool dependency bison>=1.0: found bison-2.7.1
=> Tool dependency gmake>=3.81: found gmake-3.82nb6
=> Tool dependency pkg-config>=0.25: found pkg-config-0.28
=> Build dependency x11-links>=0.72: found x11-links-0.74
=> Build dependency python27>=2.7.1nb2: found python27-2.7.4
=> Build dependency libxml2>=2.8.0nb2: found libxml2-2.9.0nb3
===> Overriding tools for MesaLib-7.11.2
===> Extracting for MesaLib-7.11.2
/bin/cp /usr/pkgsrc-cvs/graphics/MesaLib/files/gen_matypes.awk 
/usr/obj/pkg/graphics/MesaLib/work.x86_64/Mesa-7.11.2/src/mesa/x86
/bin/cp /usr/pkgsrc-cvs/graphics/MesaLib/files/gen_matypes.sh 
/usr/obj/pkg/graphics/MesaLib/work.x86_64/Mesa-7.11.2/src/mesa/x86
/bin/chmod a+x 
/usr/obj/pkg/graphics/MesaLib/work.x86_64/Mesa-7.11.2/src/mesa/x86/gen_matypes.sh
===> Patching for MesaLib-7.11.2
=> Applying pkgsrc patches for MesaLib-7.11.2
===> Creating toolchain wrappers for MesaLib-7.11.2
===> Configuring for MesaLib-7.11.2
cd /usr/obj/pkg/graphics/MesaLib/work.x86_64/Mesa-7.11.2 && /usr/bin/make 
configure
aclocal 
autoconf 
=> Modifying GNU configure scripts to avoid --recheck
=> Replacing config-guess with pkgsrc versions
=> Replacing config-sub with pkgsrc versions
=> Replacing install-sh with pkgsrc version
=> Adding run-time search paths to pkg-config files.
INFO: [subst.mk:pkgconfig] Nothing changed in ./src/mesa/drivers/dri/dri.pc.in.
checking build system type... x86_64--netbsd
checking host system type... x86_64--netbsd
checking for x86_64--netbsd-gcc... gcc
checking whether the C compiler works... yes
checking for C compiler default output file name... a.out
checking for suffix of executables... 
checking whether we are cross compiling... no
checking for suffix of object files... o
checking whether we are using the GNU C compiler... yes
checking whether gcc accepts -g... yes
checking for gcc option to accept ISO C89... none needed
checking how to run the C preprocessor... gcc -E
checking for x86_64--netbsd-gcc... (cached) gcc
checking whether we are using the GNU C compiler... (cached) yes
checking whether gcc accepts -g... (cached) yes
checking for gcc option to accept ISO C89... (cached) none needed
checking whether we are using the GNU C++ compiler... yes
checking whether c++ accepts -g... yes
checking for gmake... make
checking for python2... no
checking for python... python
checking for makedepend... 
/usr/obj/pkg/graphics/MesaLib/work.x86_64/.tools/bin/makedepend
checking for sed... /usr/bin/sed
checking for flex... /usr/obj/pkg/graphics/MesaLib/work.x86_64/.tools/bin/flex
checking for bison... /usr/obj/pkg/graphics/MesaLib/work.x86_64/.tools/bin/bison
checking for a BSD-compatible install... /usr/bin/install -c -o root -g wheel
checking if compiling with clang... no
checking whether gcc version is sufficient... yes
checking pkg-config is at least version 0.9.0... yes
checking whether gcc supports -fvisibility=hidden... yes
checking whether c++ supports -fvisibility=hidden... yes
checking whether to enable assembly... yes, x86_64
checking for gcc option to produce PIC... -fPIC
checking for dlopen... yes
checking for posix_memalign... yes
configure: error: Driver 'xlib,osmesa' is not a valid option
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc-cvs/graphics/MesaLib
*** Error code 1

Stop.
make: stopped in /usr/pkgsrc-cvs/graphics/MesaLib