Postfix is not installable on a base Red Hat install, because the postfix spec includes this little gem that needs to be rewritten using sed: # Put db3 in the chroot jail, but only if the soname is correct %triggerin -- db3 %{copy_cmd} DBVER=`ldd %{_libexecdir}/postfix/pickup |grep libdb |perl -pi -e "s,\s+,,g;s,=> .*,,"` if [ -e "/lib/$DBVER" ]; then copy "/lib/$DBVER" %{ROOT}/lib fi Perl cannot be used in specs! It may or may not be installed.... When installing postfix on systems which don't have or need perl, the install fails in the %post phase because of this.
Encountered this today on a machine where I've protected perl. With sed, one fix would be: DBVER=`ldd /usr/libexec/postfix/pickup |grep libdb |sed s,[[:blank:]],,g;s,=>.*,,"`