As seen in the cfengine code http://www.cfengine.org/src-mirror/prototypes.h the deceleration for setnetgrent() uses type void while /usr/include/netdb.h itself defines setnetgrent() as type int. This results in the cfengine build to failing when HAVE_GETNETGRENT is not defined. I'm using sys-libs/db-4.2.52_p2 with "-doc -java -tcltk" This problem showed up for me while building cfengine on a uClibc system. This problem seems to be an old one http://lists.gnu.org/archive/html/help-cfengine/2004-05/msg00011.html
Created attachment 42503 [details, diff] cfengine-2.1.10-setnetgrent.patch Patch that fixes deceleration of setnetgrent
Created attachment 42504 [details, diff] cfengine-2.1.10-r1.ebuild.diff ebuild changes. Also adds gnuconfig_update (needed for atleast uClibc)
reported and fixed in upstream, so it will be included as part of 2.1.11. A patched 2.1.10 will be in portage shortly.
fixed in .10-r1