PGXS should be set with := not =, as specified in the documentation,

to avoid useless multiple executions of pg_config.

contrib/btree_gist/Makefile

@@ -13,7 +13,7 @@ REGRESS     = init int2 int4 int8 float4 float8 cash oid timestamp timestamptz t
               date interval macaddr inet cidr text varchar char bytea bit varbit numeric
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/btree_gist

contrib/chkpass/Makefile

-# $PostgreSQL: pgsql/contrib/chkpass/Makefile,v 1.6 2004/08/20 20:13:02 momjian Exp $
+# $PostgreSQL: pgsql/contrib/chkpass/Makefile,v 1.7 2005/09/27 17:13:00 tgl Exp $
 
 MODULE_big = chkpass
 OBJS = chkpass.o
@@ -7,7 +7,7 @@ DATA_built = chkpass.sql
 DOCS = README.chkpass
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/chkpass

contrib/cube/Makefile

-# $PostgreSQL: pgsql/contrib/cube/Makefile,v 1.13 2005/07/24 23:30:09 tgl Exp $
+# $PostgreSQL: pgsql/contrib/cube/Makefile,v 1.14 2005/09/27 17:13:00 tgl Exp $
 
 MODULE_big = cube
 OBJS= cube.o cubeparse.o
@@ -12,7 +12,7 @@ EXTRA_CLEAN = cubeparse.c cubeparse.h cubescan.c y.tab.c y.tab.h
 SHLIB_LINK += $(filter -lm, $(LIBS))
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/cube

contrib/dbase/Makefile

-# $PostgreSQL: pgsql/contrib/dbase/Makefile,v 1.7 2005/03/25 18:17:10 momjian Exp $
+# $PostgreSQL: pgsql/contrib/dbase/Makefile,v 1.8 2005/09/27 17:13:01 tgl Exp $
 
 PROGRAM = dbf2pg
 OBJS	= dbf.o dbf2pg.o endian.o
@@ -16,7 +16,7 @@ MAN = dbf2pg.1			# XXX not implemented
 
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/dbase

contrib/dblink/Makefile

-# $PostgreSQL: pgsql/contrib/dblink/Makefile,v 1.9 2004/08/20 20:13:03 momjian Exp $
+# $PostgreSQL: pgsql/contrib/dblink/Makefile,v 1.10 2005/09/27 17:13:01 tgl Exp $
 
 MODULE_big = dblink
 PG_CPPFLAGS = -I$(libpq_srcdir)
@@ -11,7 +11,7 @@ REGRESS = dblink
 
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/dblink

contrib/dbmirror/Makefile

-# $PostgreSQL: pgsql/contrib/dbmirror/Makefile,v 1.4 2004/11/04 06:09:19 neilc Exp $
+# $PostgreSQL: pgsql/contrib/dbmirror/Makefile,v 1.5 2005/09/27 17:13:01 tgl Exp $
 
 MODULES = pending
 SCRIPTS = clean_pending.pl DBMirror.pl
@@ -6,7 +6,7 @@ DATA = AddTrigger.sql MirrorSetup.sql slaveDatabase.conf
 DOCS = README.dbmirror
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/dbmirror

contrib/earthdistance/Makefile

-# $PostgreSQL: pgsql/contrib/earthdistance/Makefile,v 1.15 2005/07/24 23:30:09 tgl Exp $
+# $PostgreSQL: pgsql/contrib/earthdistance/Makefile,v 1.16 2005/09/27 17:13:02 tgl Exp $
 
 MODULES = earthdistance
 DATA_built = earthdistance.sql
@@ -8,7 +8,7 @@ REGRESS = earthdistance
 SHLIB_LINK += $(filter -lm, $(LIBS))
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/earthdistance

contrib/fulltextindex/Makefile

-# $PostgreSQL: pgsql/contrib/fulltextindex/Makefile,v 1.13 2004/08/20 20:13:04 momjian Exp $
+# $PostgreSQL: pgsql/contrib/fulltextindex/Makefile,v 1.14 2005/09/27 17:13:02 tgl Exp $
 
 MODULES = fti
 DATA_built = fti.sql
@@ -6,7 +6,7 @@ DOCS = README.fti
 SCRIPTS = fti.pl
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/fulltextindex

contrib/fuzzystrmatch/Makefile

-# $PostgreSQL: pgsql/contrib/fuzzystrmatch/Makefile,v 1.5 2004/08/20 20:13:04 momjian Exp $
+# $PostgreSQL: pgsql/contrib/fuzzystrmatch/Makefile,v 1.6 2005/09/27 17:13:03 tgl Exp $
 
 MODULE_big = fuzzystrmatch
 SRCS += fuzzystrmatch.c dmetaphone.c
@@ -7,7 +7,7 @@ DATA_built = fuzzystrmatch.sql
 DOCS = README.fuzzystrmatch README.soundex
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/fuzzystrmatch

contrib/intagg/Makefile

@@ -2,14 +2,14 @@
 # Makefile for integer aggregator
 # Copyright (C) 2001 Digital Music Network.
 # by Mark L. Woodward
-# $PostgreSQL: pgsql/contrib/intagg/Makefile,v 1.5 2004/08/20 20:13:04 momjian Exp $
+# $PostgreSQL: pgsql/contrib/intagg/Makefile,v 1.6 2005/09/27 17:13:03 tgl Exp $
 
 MODULES = int_aggregate
 DATA_built = int_aggregate.sql
 DOCS = README.int_aggregate
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/intagg

contrib/intarray/Makefile

-# $PostgreSQL: pgsql/contrib/intarray/Makefile,v 1.11 2004/08/20 20:13:04 momjian Exp $
+# $PostgreSQL: pgsql/contrib/intarray/Makefile,v 1.12 2005/09/27 17:13:04 tgl Exp $
 
 MODULE_big = _int
 OBJS = _int_bool.o _int_gist.o _int_op.o _int_tool.o _intbig_gist.o 
@@ -7,7 +7,7 @@ DOCS = README.intarray
 REGRESS = _int
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/intarray

contrib/isbn_issn/Makefile

-# $PostgreSQL: pgsql/contrib/isbn_issn/Makefile,v 1.13 2004/08/20 20:13:04 momjian Exp $
+# $PostgreSQL: pgsql/contrib/isbn_issn/Makefile,v 1.14 2005/09/27 17:13:04 tgl Exp $
 
 MODULES = isbn_issn
 DATA_built = isbn_issn.sql
 DOCS = README.isbn_issn
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/isbn_issn

contrib/lo/Makefile

-# $PostgreSQL: pgsql/contrib/lo/Makefile,v 1.13 2004/08/20 20:13:05 momjian Exp $
+# $PostgreSQL: pgsql/contrib/lo/Makefile,v 1.14 2005/09/27 17:13:04 tgl Exp $
 
 MODULES = lo
 DATA_built = lo.sql
@@ -6,7 +6,7 @@ DATA = lo_drop.sql lo_test.sql
 DOCS = README.lo
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/lo

contrib/ltree/Makefile

@@ -7,7 +7,7 @@ DOCS = README.ltree
 REGRESS = ltree
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/ltree

contrib/mSQL-interface/Makefile

 #
-# $PostgreSQL: pgsql/contrib/mSQL-interface/Makefile,v 1.9 2004/08/20 20:13:05 momjian Exp $
+# $PostgreSQL: pgsql/contrib/mSQL-interface/Makefile,v 1.10 2005/09/27 17:13:05 tgl Exp $
 #
 
 NAME	= mpgsql
@@ -10,7 +10,7 @@ OBJS	= mpgsql.o
 PG_CPPFLAGS = -I$(libpq_srcdir)
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/mSQL-interface

contrib/oid2name/Makefile

-# $PostgreSQL: pgsql/contrib/oid2name/Makefile,v 1.7 2005/03/25 18:17:11 momjian Exp $
+# $PostgreSQL: pgsql/contrib/oid2name/Makefile,v 1.8 2005/09/27 17:13:06 tgl Exp $
 
 PROGRAM = oid2name
 OBJS	= oid2name.o
@@ -9,7 +9,7 @@ PG_LIBS = $(libpq_pgport)
 DOCS = README.oid2name
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/oid2name

contrib/pg_buffercache/Makefile

-# $PostgreSQL: pgsql/contrib/pg_buffercache/Makefile,v 1.1 2005/03/12 15:36:24 neilc Exp $
+# $PostgreSQL: pgsql/contrib/pg_buffercache/Makefile,v 1.2 2005/09/27 17:13:07 tgl Exp $
 
 MODULE_big = pg_buffercache
 OBJS	= pg_buffercache_pages.o
@@ -7,7 +7,7 @@ DATA_built = pg_buffercache.sql
 DOCS = README.pg_buffercache
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/pg_buffercache

contrib/pg_trgm/Makefile

@@ -10,7 +10,7 @@ REGRESS = pg_trgm
 
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/pg_trgm

contrib/pgbench/Makefile

-# $PostgreSQL: pgsql/contrib/pgbench/Makefile,v 1.13 2005/03/25 18:17:11 momjian Exp $
+# $PostgreSQL: pgsql/contrib/pgbench/Makefile,v 1.14 2005/09/27 17:13:08 tgl Exp $
 
 PROGRAM = pgbench
 OBJS	= pgbench.o
@@ -9,7 +9,7 @@ PG_LIBS = $(libpq_pgport)
 DOCS = README.pgbench README.pgbench_jis
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/pgbench

contrib/pgcrypto/Makefile

 #
-# $PostgreSQL: pgsql/contrib/pgcrypto/Makefile,v 1.22 2005/08/13 02:06:20 momjian Exp $
+# $PostgreSQL: pgsql/contrib/pgcrypto/Makefile,v 1.23 2005/09/27 17:13:08 tgl Exp $
 #
 
 INT_SRCS = md5.c sha1.c sha2.c internal.c blf.c rijndael.c \
@@ -44,7 +44,7 @@ REGRESS = init md5 sha1 hmac-md5 hmac-sha1 blowfish rijndael \
 
 
 ifdef USE_PGXS
-PGXS = $(shell pg_config --pgxs)
+PGXS := $(shell pg_config --pgxs)
 include $(PGXS)
 else
 subdir = contrib/pgcrypto