postfix build fails with clang error

[terry at digital-outpost.com]

I can build postfix by itself but if I add any variants it fails with 
the error below. I'm trying to build postfix +dovecot_sasl +mysql5 +pcre 
+tls and all the added variants get built but it fails on postfix. Any 
help greatly appreciated.

Fresh OS X 10.8.5 on MacPro3,1, Quad-Core Intel Xeon, 2.8 GHz, 4GB RAM
Error occurred with with Xcode 5.1 so I removed thinking some new clang 
problem and installed Xcode 4.6.3, but same error.

Here's the tail end of  
/opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_mail_postfix/postfix/main.log

...
:info:build cp libmaster.a ../../lib/libmaster.a
:info:build /usr/bin/clang -DNO_PCRE -arch x86_64 -DHAS_MYSQL 
-I/opt/local/include/mysql5/mysql -Wmissing-prototypes -Wformat 
-Wno-comment -DBIND_8_COMPAT -DNO_NETINFO 
-DRESOLVE_H_NEEDS_ARPA_NAMESER_COMPAT_H -g -Os -I. -I../../include 
-DMACOSX -o master master.o master_conf.o master_ent.o master_sig.o 
master_avail.o master_spawn.o master_service.o master_status.o 
master_listen.o master_vars.o master_wakeup.o master_watch.o 
master_flow.o master_monitor.o ../../lib/libglobal.a ../../lib/libutil.a 
-L/opt/local/lib -R/opt/local/lib -L/opt/local/lib -arch x86_64 -lresolv 
-L/opt/local/lib/mysql5/mysql -lmysqlclient -lz -lm -lresolv
:info:build ranlib ../../lib/libmaster.a
:info:build clang: error: unknown argument: '-R/opt/local/lib' 
[-Wunused-command-line-argument-hard-error-in-future]
:info:build clang: note: this will be a hard error (cannot be downgraded 
to a warning) in the future
:info:build make: *** [master] Error 1
:info:build make: *** Waiting for unfinished jobs....
:info:build make: Leaving directory 
`/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_mail_postfix/postfix/work/postfix-2.11.0/src/master'
:info:build make: *** [update] Error 1
:info:build make: Leaving directory 
`/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_mail_postfix/postfix/work/postfix-2.11.0'
:info:build Command failed:  cd 
"/opt/local/var/macports/build/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_mail_postfix/postfix/work/postfix-2.11.0" 
&& /usr/bin/make -j4 -w
:info:build Exit code: 2
:error:build org.macports.build for port postfix returned: command 
execution failed
:debug:build Error code: CHILDSTATUS 93866 2
:debug:build Backtrace: command execution failed
while executing
"system -nice 0 $fullcmdstring"
("eval" body line 1)
invoked from within
"eval system $notty $nice \$fullcmdstring"
invoked from within
"command_exec build"
(procedure "portbuild::build_main" line 8)
invoked from within
"$procedure $targetname"
:info:build Warning: targets not executed for postfix: 
org.macports.activate org.macports.build org.macports.destroot 
org.macports.install
:notice:build Please see the log file for port postfix for details:
/opt/local/var/macports/logs/_opt_local_var_macports_sources_rsync.macports.org_release_tarballs_ports_mail_postfix/postfix/main.log