syslibs.m4 #88 - possible improvement from Ozik

dev/m4/syslibs.m4

@@ -1,5 +1,19 @@
+
+# SYSLIBS.M4
+
+# We take system libraries out of arguments to the linker
+# to prevent system libraries from pre-empting custom user
+# library locations.
+# Cf. https://code.google.com/p/exm-issues/issues/detail?id=546
+
 AC_MSG_NOTICE([Generating system-libs.txt])
-# We take system libraries out of arguments to the linker (#546)
+
+AC_PATH_PROG([LDCONFIG],[ldconfig],[no],["$PATH:/sbin"])
+if [[ ${LDCONFIG} == no ]]
+then
+    AC_MSG_ERROR([Could not find ldconfig.])
+fi
+
 if [[ ${USE_MAC} == "no" ]]
 then
     # This does not work on the Mac