adjust order of checking SL5 and setting avariable

SiteTests/FroNtier/tests/CE-cms-frontier

 #!/bin/bash
 
 echo "<h2>Test of FroNtier under CMSSW</h2>"
-
 # Source the CMS environment
 echo "<h3>Sourcing the CMS environment</h3>"
-export SCRAM_ARCH=slc5_ia32_gcc434
-export BUILD_ARCH=$SCRAM_ARCH
-if [ -n "$VO_CMS_SW_DIR" ] ; then
-    SW_DIR=$VO_CMS_SW_DIR
-elif [ -n "$OSG_APP" ] ; then
+if [ -n "$OSG_APP" ] ; then
     SW_DIR=$OSG_APP/cmssoft/cms
+elif [ -n "$VO_CMS_SW_DIR" ] ; then
+    SW_DIR=$VO_CMS_SW_DIR
 else
     echo "ERROR: Neither VO_CMS_SW_DIR nor OSG_APP defined"
     exit $SAME_ERROR
 fi
-echo "<pre>"
-source $SW_DIR/cmsset_default.sh
-result=$?
-echo "</pre>"
-if [ $result != 0 ]
-    then
-    echo "ERROR: $SW_DIR/cmsset_default.sh non existent or non readable"
-    exit $SAME_ERROR
+if [ `uname -n|cut -d. -f2-` == "cern.ch" ] ; then
+    echo "running at CERN, hardset \$SW_DIR to /afs/cern.ch/cms/sw"
+    export SW_DIR=/afs/cern.ch/cms/sw/
 fi
 
-#
+echo "CMS software location SW_DIR=" $SW_DIR
+tmpfile=`mktemp /tmp/tmp.XXXXXXXXXX`
+echo "<pre>"
+
+
 # check for SL5
-#
 libc25=1
 if ! [ -f $SW_DIR/common/cmsos ] ; then
  echo "$SW_DIR/common/cmsos not found - force to SL5"
@@ -57,6 +52,29 @@ if  [ $libc25 == "0" ] ; then
 fi
 
 
+# this test requires SLC5 arch, currently
+export SCRAM_ARCH=slc5_ia32_gcc434
+export BUILD_ARCH=$SCRAM_ARCH
+source $SW_DIR/cmsset_default.sh > $tmpfile 2>&1
+result=$?
+cat $tmpfile
+echo "</pre>"
+grep 'Your shell is not able to find' $tmpfile > /dev/null
+result2=$?
+rm -f $tmpfile
+if [ $result != 0 ]
+    then
+    echo "ERROR: $SW_DIR/cmsset_default.sh non existent or non readable"
+    exit $SAME_ERROR
+fi
+if [ $result2 == 0 ]
+    then
+    echo "ERROR: $SW_DIR/cmsset_default.sh failed"
+    # temporarely set this to WARNING to allow soft fail for SL4 clusters
+    exit $SAME_WARNING
+fi
+
+
 # Execute main test script
 echo "<h3>Executing the FroNtier test</h3>"
 echo "<pre>"