stereograph version 0.30a-6 failed to build on i386

stereograph version 0.30a-6 failed to build on i386
Link to failed build: https://launchpad.net/ubuntu/+archive/test-rebuild-20110329/+buildjob/2411029

Direct link to the build log: https://launchpad.net/ubuntu/+archive/test-rebuild-20110329/+buildjob/2411029/+files/buildlog_ubuntu-natty-i386.stereograph_0.30a-6_FAILEDTOBUILD.txt.gz

This log snippet might be of interest, since it triggered the matcher 'Purging chroot-autobuild'.
Excerpt 813 lines into the build log:

renderer.c:317:2: warning: incompatible implicit declaration of built-in function 'memcpy'
renderer.c: In function 'ZoomScan':
renderer.c:454:3: warning: incompatible implicit declaration of built-in function 'memcpy'
renderer.c: In function 'ZoomAAScan':
renderer.c:523:3: warning: incompatible implicit declaration of built-in function 'memcpy'
gcc -Wall -Dlinux -g -O2 -c -o gfxio.o gfxio.c
gfxio.c: In function 'Generate_Sinline_Texture':
gfxio.c:902:9: warning: 'a' may be used uninitialized in this function
gcc -lm /usr/lib/libpng.so /usr/lib/libz.so stereograph.o renderer.o gfxio.o -o stereograph
gcc: /usr/lib/libpng.so: No such file or directory
gcc: /usr/lib/libz.so: No such file or directory
make[1]: *** [stereograph] Error 1
make[1]: Leaving directory `/build/buildd/stereograph-0.30a'
make: *** [build-stamp] Error 2
dpkg-buildpackage: error: debian/rules build gave error exit status 2
******************************************************************************
Build finished at 20110408-1454
FAILED [dpkg-buildpackage died]
Purging chroot-autobuild/build/buildd/stereograph-0.30a