=> Bootstrap dependency digest>=20010302: found digest-20121220
=> Checksum SHA1 OK for ico-1.0.4.tar.bz2
=> Checksum RMD160 OK for ico-1.0.4.tar.bz2
===> Installing dependencies for ico-1.0.4
=> Tool dependency pkg-config>=0.25: found pkg-config-0.28
=> Build dependency x11-links>=0.72: found x11-links-0.74
=> Full dependency pth>=2.0.0nb2: found pth-2.0.7nb3
===> Overriding tools for ico-1.0.4
===> Extracting for ico-1.0.4
===> Patching for ico-1.0.4
===> Creating toolchain wrappers for ico-1.0.4
ERROR: zlib>=1.1.4nb1 is not installed; can't buildlink files.
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/x11/ico
*** Error code 1

Stop.
bmake: stopped in /usr/pkgsrc/x11/ico