Index: trunk/psLib/configure.ac
===================================================================
--- trunk/psLib/configure.ac	(revision 4816)
+++ trunk/psLib/configure.ac	(revision 4819)
@@ -12,11 +12,19 @@
 AC_SUBST(PSLIB_LT_VERSION,$PSLIB_LT_VERSION)
 
+dnl Determine the location of GNU sed
+AC_CHECK_PROGS([SED],[gsed sed])
+if test "${SED}" == ""
+then
+  AC_MSG_ERROR([GNU SED is required.])
+fi
+AC_SUBST(SED,[${SED}])
+
 SUBDIR="etc src test" dnl don't include 'swig', as it is optional
 
 SRCPATH="`pwd`/src"
 SRCDIRS="sys astro db fft fits imageops math mathtypes types xml"
-SRCINC=`echo "${SRCDIRS=}" | sed "s|\(\\w\+\)|-I\${SRCPATH=}/\1|g"`
-
-SRCSUBLIBS=`echo "${SRCDIRS=}" | sed "s|\(\\w\+\)|\1/libpslib\1.la|g"`
+SRCINC=`echo "${SRCDIRS=}" | ${SED} "s|\(\\w\+\)|-I\${SRCPATH=}/\1|g"`
+
+SRCSUBLIBS=`echo "${SRCDIRS=}" | ${SED} "s|\(\\w\+\)|\1/libpslib\1.la|g"`
 AC_SUBST(SRCSUBLIBS,${SRCSUBLIBS=})
 CFLAGS="${CFLAGS=} -I${SRCPATH=} ${SRCINC=}"
@@ -37,5 +45,6 @@
 case $host in
   *-apple-darwin*)
-    CFLAGS="${CFLAGS=} -Wno-long-double"
+dnl    CFLAGS="${CFLAGS=} -Wno-long-double"
+dnl GCC 4.0 on OSX seems to hate that.
     ;;
 esac
@@ -193,4 +202,5 @@
 PSLIB_LIBS="${PSLIB_LIBS=} `${XML_CONFIG} --libs`"
 PSLIB_CFLAGS="${PSLIB_CFLAGS=} `${XML_CONFIG} --cflags`"
+
 
 dnl ------------------- SWIG options ---------------------