Upgrade dev-db/postgresql-base to 9.0.3-r1 broke all programm linked with libpq Postfix, dovecot unable to start. revdep-rebuild didn't find any problem. After change LDPATH in /etc/env.d/50postgresql-94-9.0 libpq usable. LDPATH changed from "/usr/lib64/postgresql-9.0/lib" to "/usr/lib64/postgresql-9.0/lib64".
The relevant section in dev-db/postgresql-base-9.0.3-r1: cat >"${T}/50postgresql-94-${SLOT}" <<-__EOF__ LDPATH=${EROOT%/}/usr/$(get_libdir)/postgresql-${SLOT}/lib MANPATH=${EROOT%/}/usr/share/postgresql-${SLOT}/man __EOF__ So, the problem lies somewhere else. Where does pg_config say libdir is?
emerge --sync and re-emerge postgresql. issue was in the profile and is already fixed.