lockfile-progs version 0.1.15 failed to build in oneiric

lockfile-progs version 0.1.15 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2704206

Details about the rebuild:
http://people.ubuntuwire.org/~wgrant/rebuild-ftbfs-test/test-rebuild-20110816-oneiric.html

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2704206/+files/buildlog_ubuntu-oneiric-i386.lockfile-progs_0.1.15_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 505 lines into the build log:

test -f lockfile-progs.c
make[1]: Leaving directory `/build/buildd/lockfile-progs-0.1.15'
   dh_auto_configure
   dh_auto_build
make[1]: Entering directory `/build/buildd/lockfile-progs-0.1.15'
cc -g -Wall -Wformat-security -Werror -O2 -c -o lockfile-progs.o lockfile-progs.c
lockfile-progs.c: In function 'chk':
lockfile-progs.c:69:9: error: variable 'rc' set but not used [-Werror=unused-but-set-variable]
cc1: all warnings being treated as errors

make[1]: *** [lockfile-progs.o] Error 1
make[1]: Leaving directory `/build/buildd/lockfile-progs-0.1.15'
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 20110818-0141
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/lockfile-progs-0.1.15