theorur version 0.5.5-0ubuntu1 failed to build in oneiric

theorur version 0.5.5-0ubuntu1 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2712960

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/2712960/+files/buildlog_ubuntu-oneiric-amd64.theorur_0.5.5-0ubuntu1_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 1667 lines into the build log:

/build/buildd/theorur-0.5.5/tooltips.c:45: undefined reference to `g_type_check_instance_cast'
/build/buildd/theorur-0.5.5/tooltips.c:45: undefined reference to `gtk_tooltips_set_tip'
/build/buildd/theorur-0.5.5/tooltips.c:46: undefined reference to `g_type_check_instance_cast'
/build/buildd/theorur-0.5.5/tooltips.c:46: undefined reference to `gtk_tooltips_set_tip'
/build/buildd/theorur-0.5.5/tooltips.c:47: undefined reference to `g_type_check_instance_cast'
/build/buildd/theorur-0.5.5/tooltips.c:47: undefined reference to `gtk_tooltips_set_tip'
/build/buildd/theorur-0.5.5/tooltips.c:49: undefined reference to `gtk_combo_get_type'
/build/buildd/theorur-0.5.5/tooltips.c:49: undefined reference to `g_type_check_instance_cast'
/build/buildd/theorur-0.5.5/tooltips.c:49: undefined reference to `g_type_check_instance_cast'
/build/buildd/theorur-0.5.5/tooltips.c:49: undefined reference to `gtk_tooltips_set_tip'
collect2: ld returned 1 exit status
make[1]: *** [theorur] Error 1
make[1]: Leaving directory `/build/buildd/theorur-0.5.5'
make: *** [build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110824-0029
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/theorur-0.5.5