neko version 1.8.1-5 failed to build on amd64 with GCC-4.6/oneiric

neko version 1.8.1-5 failed to build on amd64 with GCC-4.6/oneiric
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110413/+buildjob/2463030

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/2463030/+files/buildlog_ubuntu-natty-amd64.neko_1.8.1-5_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 1119 lines into the build log:

gcc -shared -L../../bin -pthread -lneko -L/build/buildd/neko-1.8.1/src -L/usr/lib -L/usr/lib/mysql -o ../../bin/ui.ndll -lgthread-2.0 ui.o
Compiling regexp...
gcc -O3 -DEAPI -fPIC -pthread $(pkg-config --cflags apr-1) -pthread -c -I../../vm -I/usr/include regexp.c
gcc -shared -L../../bin -pthread -lneko -L/build/buildd/neko-1.8.1/src -L/usr/lib -L/usr/lib/mysql -o ../../bin/regexp.ndll -lpcre regexp.o
Compiling mysql...
gcc -O3 -DEAPI -fPIC -pthread $(pkg-config --cflags apr-1) -pthread -c -I../../vm -I/usr/include/mysql mysql.c
gcc -shared -L../../bin -pthread -lneko -L/build/buildd/neko-1.8.1/src -L/usr/lib -L/usr/lib/mysql -o ../../bin/mysql.ndll -lmysqlclient mysql.o
../bin/neko nekoml -nostd neko/Main.nml nekoml/Main.nml core/*.nml -pack ../bin/nekoml.std
../bin/neko: symbol lookup error: ../bin/zlib.ndll: undefined symbol: deflateInit_
Called from tools/install.neko line 357
Uncaught exception - Error 32512 : aborted
make[1]: *** [libs] Error 1
make[1]: Leaving directory `/build/buildd/neko-1.8.1'
make: *** [build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110424-2323
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/neko-1.8.1