Index: /issm/trunk-jpl/m4/issm_options.m4
===================================================================
--- /issm/trunk-jpl/m4/issm_options.m4	(revision 25120)
+++ /issm/trunk-jpl/m4/issm_options.m4	(revision 25121)
@@ -371,4 +371,7 @@
 					MEXLIB=$(cat conftest.tmp | grep LINKLIBS | sed -e "s/LINKLIBS ://g")
 					MEXEXT=$(cat conftest.tmp | grep LDEXT | sed -e "s/LDEXT ://g" | awk '{print $[1]}')
+					if test -z "${MEXEXT}"; then
+					 cat conftest.tmp
+					fi
 					rm -f conftest.tmp
 				fi
@@ -381,5 +384,5 @@
 		AC_MSG_RESULT([done])
 		if test -z "${MEXEXT}"; then
-			AC_MSG_ERROR([Couldn't find mex... check your installation of MATLAB])
+			AC_MSG_ERROR([Couldn't use MATLAB's mex... check manual compilation with MATLAB or error message above])
 		fi