ssss version 0.5-2 failed to build in oneiric

ssss version 0.5-2 failed to build in oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110816/+build/2712114

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/2712114/+files/buildlog_ubuntu-oneiric-amd64.ssss_0.5-2_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 535 lines into the build log:

ssss.c:(.text+0x17a6): undefined reference to `__gmpz_xor'
ssss.c:(.text+0x17c9): undefined reference to `__gmpz_clear'
ssss.c:(.text+0x1873): undefined reference to `__gmpz_clear'
ssss.c:(.text+0x1891): undefined reference to `__gmpz_clear'
/tmp/ccipZ77W.o: In function `field_deinit':
ssss.c:(.text+0x246): undefined reference to `__gmpz_clear'
/tmp/ccipZ77W.o: In function `field_add':
ssss.c:(.text+0x4e1): undefined reference to `__gmpz_xor'
/tmp/ccipZ77W.o: In function `horner':
ssss.c:(.text+0xbbf): undefined reference to `__gmpz_xor'
collect2: ld returned 1 exit status
make[1]: *** [ssss-split] Error 1
make[1]: Leaving directory `/build/buildd/ssss-0.5'
make: *** [build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110823-2218
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/ssss-0.5