redis version 2:2.0.1-2 failed to build on amd64 with GCC-4.6/oneiric

redis version 2:2.0.1-2 failed to build on amd64 with GCC-4.6/oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2467254

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/2467254/+files/buildlog_ubuntu-natty-amd64.redis_2%3A2.0.1-2_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 332 lines into the build log:

cc -c -std=c99 -pedantic -O2 -Wall -W -g -rdynamic -ggdb zmalloc.c
cc -c -std=c99 -pedantic -O2 -Wall -W -g -rdynamic -ggdb lzf_c.c
cc -c -std=c99 -pedantic -O2 -Wall -W -g -rdynamic -ggdb lzf_d.c
cc -c -std=c99 -pedantic -O2 -Wall -W -g -rdynamic -ggdb pqsort.c
cc -c -std=c99 -pedantic -O2 -Wall -W -g -rdynamic -ggdb zipmap.c
cc -c -std=c99 -pedantic -O2 -Wall -W -g -rdynamic -ggdb sha1.c
cc -o redis-server -std=c99 -pedantic -O2 -Wall -W -lm -pthread -g -rdynamic -ggdb adlist.o ae.o anet.o dict.o redis.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o
redis.o: In function `computeObjectSwappability':
/build/buildd/redis-2.0.1/redis.c:9271: undefined reference to `log'
collect2: ld returned 1 exit status
make[1]: *** [redis-server] Error 1
make[1]: Leaving directory `/build/buildd/redis-2.0.1'
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 20110426-0656
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/redis-2.0.1