pinball version 0.3.1-13 failed to build on amd64 with GCC-4.6/oneiric

pinball version 0.3.1-13 failed to build on amd64 with GCC-4.6/oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2465077

Details about the rebuild:
https://lists.ubuntu.com/archives/ubuntu-devel/2011-April/033042.html

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2465077/+files/buildlog_ubuntu-natty-amd64.pinball_0.3.1-13_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 1509 lines into the build log:

g++ -DHAVE_CONFIG_H -I. -I.. -I../addon -I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT -g -O2 -c -o AlignVisitor.o AlignVisitor.cpp
g++ -DHAVE_CONFIG_H -I. -I.. -I../addon -I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT -g -O2 -c -o AllegroVisitor.o AllegroVisitor.cpp
g++ -DHAVE_CONFIG_H -I. -I.. -I../addon -I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT -g -O2 -c -o AmbientLightVisitor.o AmbientLightVisitor.cpp
g++ -DHAVE_CONFIG_H -I. -I.. -I../addon -I/usr/include/SDL -D_GNU_SOURCE=1 -D_REENTRANT -g -O2 -c -o Behavior.o Behavior.cpp
Behavior.cpp: In constructor 'Behavior::Behavior()':
Behavior.cpp:15:12: error: 'NULL' was not declared in this scope
make[3]: *** [Behavior.o] Error 1
make[3]: Leaving directory `/build/buildd/pinball-0.3.1/base'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/build/buildd/pinball-0.3.1'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/build/buildd/pinball-0.3.1'
dh_auto_build: make -j1 returned exit code 2
make: *** [build] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110425-1427
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/pinball-0.3.1