desktop-webmail version 002-0ubuntu2 failed to build in oneiric

desktop-webmail version 002-0ubuntu2 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2691343

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/2691343/+files/buildlog_ubuntu-oneiric-i386.desktop-webmail_002-0ubuntu2_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 1230 lines into the build log:

make[3]: Entering directory `/build/buildd/desktop-webmail-002/src'
gcc -DHAVE_CONFIG_H -I. -I.. -Wall -Werror -g -O2 -pthread -I/usr/include/gtk-2.0 -I/usr/lib/i386-linux-gnu/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/gdk-pixbuf-2.0 -I/usr/include/pango-1.0 -I/usr/include/gio-unix-2.0/ -I/usr/include/glib-2.0 -I/usr/lib/i386-linux-gnu/glib-2.0/include -I/usr/include/pixman-1 -I/usr/include/freetype2 -I/usr/include/libpng12 -Dpkgdatadir=\"/usr/share/desktop-webmail\" -Dsysconfpkgdir=\"/etc/desktop-webmail\" -g -O2 -c -o desktop_webmail-desktop-webmail.o `test -f 'desktop-webmail.c' || echo './'`desktop-webmail.c
desktop-webmail.c: In function 'run_gtk_config':
desktop-webmail.c:416:21: error: variable 'column' set but not used [-Werror=unused-but-set-variable]
cc1: all warnings being treated as errors

make[3]: *** [desktop_webmail-desktop-webmail.o] Error 1
make[3]: Leaving directory `/build/buildd/desktop-webmail-002/src'
make[2]: *** [all-recursive] Error 1
make[2]: Leaving directory `/build/buildd/desktop-webmail-002'
make[1]: *** [all] Error 2
make[1]: Leaving directory `/build/buildd/desktop-webmail-002'
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 20110817-0138
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/desktop-webmail-002