modglue version 1.17-2 failed to build on i386

modglue version 1.17-2 failed to build on i386
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110329/+buildjob/2404563

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110329/+buildjob/2404563/+files/buildlog_ubuntu-natty-i386.modglue_1.17-2_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 929 lines into the build log:

libtool --tag=CXX --mode=link i686-linux-gnu-g++ -o test_child_process test_child_process.o libmodglue.la
libtool: link: i686-linux-gnu-g++ -o .libs/test_child_process test_child_process.o ./.libs/libmodglue.so
i686-linux-gnu-g++ -c -D"DATETIME=\"`date | sed -e 's/ / /'`\"" -DHOSTNAME=\"`hostname`\" -D"USE_UTIL_H=0" -I../include `pkg-config sigc++-2.0 --cflags` test_pipe.cc
libtool --tag=CXX --mode=link i686-linux-gnu-g++ -o test_pipe test_pipe.o libmodglue.la
libtool: link: i686-linux-gnu-g++ -o .libs/test_pipe test_pipe.o ./.libs/libmodglue.so
/usr/bin/ld: test_pipe.o: undefined reference to symbol 'sigc::trackable::trackable()'
/usr/bin/ld: note: 'sigc::trackable::trackable()' is defined in DSO /usr/lib/libsigc-2.0.so.0 so try adding it to the linker command line
/usr/lib/libsigc-2.0.so.0: could not read symbols: Invalid operation
collect2: ld returned 1 exit status
make[2]: *** [test_pipe] Error 1
make[2]: Leaving directory `/build/buildd/modglue-1.17/src'
make[1]: *** [library] Error 2
make[1]: Leaving directory `/build/buildd/modglue-1.17'
make: *** [build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110408-1612
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/modglue-1.17