>>> Unpacking source...
>>> Unpacking rbldnsd_0.996b.tar.gz to /var/tmp/portage/net-dns/rbldnsd-0.996b/work
>>> Source unpacked.
>>> Compiling source in /var/tmp/portage/net-dns/rbldnsd-0.996b/work/rbldnsd-0.996b ...
configure: rbldnsd... 0.996b (29 Mar 2008)
checking for C compiler... gcc
checking whenever the C compiler (gcc -O2 -pipe -Wl,-O1)
           can produce executables... yes
checking for ranlib... ranlib
checking for stdint.h... yes
checking for inline... yes
checking for socklen_t... yes
checking for libraries needed for connect()... ok (none needed)
checking for IPv6... yes
checking for mallinfo()... yes
checking for poll()... yes
checking for vsnprintf()... yes
checking for writev()/readv()... yes
checking for setitimer()... yes
checking for zlib support... no
configure: fatal: zlib support is requested but not found/available
 * 
 * ERROR: net-dns/rbldnsd-0.996b failed.
 * Call stack:
 *               ebuild.sh, line   49:  Called src_compile
 *             environment, line 2116:  Called die
 * The specific snippet of code:
 *       ./configure $(use_enable ipv6) $(use_enable zlib) || die "./configure failed";
 *  The die message:
 *   ./configure failed
 * 
 * If you need support, post the topmost build error, and the call stack if relevant.
 * A complete build log is located at '/var/log/portage/net-dns:rbldnsd-0.996b:20081121-130048.log'.
 * The ebuild environment file is located at '/var/tmp/portage/net-dns/rbldnsd-0.996b/temp/environment'.
 *