libdkim version 1:1.0.21-1 failed to build on amd64 with GCC-4.6/oneiric

libdkim version 1:1.0.21-1 failed to build on amd64 with GCC-4.6/oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2457318

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/2457318/+files/buildlog_ubuntu-natty-amd64.libdkim_1%3A1.0.21-1_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 431 lines into the build log:

libdkimtest.o: In function `main':
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:280: undefined reference to `DKIMVerifyInit'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:288: undefined reference to `DKIMVerifyProcess'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:296: undefined reference to `DKIMVerifyResults'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:302: undefined reference to `DKIMVerifyGetDetails'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:223: undefined reference to `DKIMSignInit'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:231: undefined reference to `DKIMSignProcess'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:245: undefined reference to `DKIMSignGetSig2'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:249: undefined reference to `DKIMSignFree'
/build/buildd/libdkim-1.0.21/src/libdkimtest.cpp:314: undefined reference to `DKIMVerifyFree'
collect2: ld returned 1 exit status
make[1]: *** [libdkimtest] Error 1
make[1]: Leaving directory `/build/buildd/libdkim-1.0.21'
make: *** [build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110424-0221
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/libdkim-1.0.21