After reading the page

A ports/lang/gcc-aux/Makefile
A ports/lang/ats/Makefile
A ports/lang/ats/files/patch-Makefile__bootstrap
svn: E120108: Error running context: The server unexpectedly closed the connection.
h97@makoto 23:54:27/150911(/export/svn-work)% echo svn update ports  
svn update ports
h97@makoto 23:54:51/150911(/export/svn-work)% history              
    6  less /export/WRKOBJDIR/ham/gnuradio-ctrlport/work/gnuradio-3.7.8/
    7  cd /export/CHROOT/usr/pkgsrc/wip/virtualbox-ose
    8  (cd /export/WRKOBJDIR/wip/virtualbox-ose/work/VirtualBox-4.3.30; diff -up configure{~,})
    9  (cd /export/WRKOBJDIR/wip/virtualbox-ose/work/VirtualBox-4.3.30; diff -up configure{~,}) > patches/patch-configure
   10  make clean
   11  make distinfo
   12  make
   13  ls patches
   14  ls -lt patches
   15  ls /export
   16  cd /export
   17  mkdir svn-work
   18  cd svn-work
   19  svn checkout https://svn.FreeBSD.org/ports/head /usr/ports
   20  svn checkout https://svn.FreeBSD.org/ports/head  ports
   21  echo svn update ports
h97@makoto 23:54:56/150911(/export/svn-work)% 

Adding following patch to /usr/ports/Mk/bsd.port.mk
may give convenient target

--- Mk/bsd.port.mk.orig	2015-09-12 00:47:22.100599000 +0900
+++ Mk/bsd.port.mk	2015-09-12 00:41:04.369753000 +0900
@@ -2934,6 +3007,31 @@ describe:
 	@${DO_NADA}
 .endif
 
+# convenience target, to display make variables from command line
+# i.e. "make show-var VARNAME=var", will print var's value
+#
+# See also:
+#       show-vars, show-subdir-var
+#
+.PHONY: show-var
+show-var:
+	@${ECHO} ${${VARNAME}:Q}
+
+# enhanced version of target above, to display multiple variables
+.PHONY: show-vars
+show-vars:
+.for VARNAME in ${VARNAMES}
+	@${ECHO} ${${VARNAME}:Q}
+.endfor
+
+# displays multiple variables as shell expressions
+# VARS is space separated list of VARNAME:shellvarname
+.PHONY: show-vars-eval
+show-vars-eval:
+.for var in ${VARS}
+	@${ECHO} ${var:C/^.*://}="${${var:C/:.*$//}:Q}"
+.endfor
+
 ################################################################
 # More standard targets start here.
 #