diff --git a/cms/patatrack/cms-patatrack/cms-patatrack-bmk.sh b/cms/patatrack/cms-patatrack/cms-patatrack-bmk.sh
index 6366a94c8ade828413fb6a7874f1c8ca86fe94ec..290eca401d3443a6db124c39afe6f7917cd9739f 100755
--- a/cms/patatrack/cms-patatrack/cms-patatrack-bmk.sh
+++ b/cms/patatrack/cms-patatrack/cms-patatrack-bmk.sh
@@ -4,7 +4,7 @@
 
 #set -x # enable debug printouts
 
-#set -e # immediate exit on error
+set -e # immediate exit on error
 
 
 function myecho(){
@@ -56,9 +56,19 @@ function validateInputArguments(){
 
   source $VO_CMS_SW_DIR/cmsset_default.sh
   [[ ! -e ${CMSSW_RELEASE} ]] && scram project CMSSW ${CMSSW_RELEASE}
-  pushd ${CMSSW_RELEASE}; eval `scramv1 runtime -sh`; popd
-  # Configure WL copy
+  cd ${CMSSW_RELEASE}/src; 
+  eval `scramv1 runtime -sh`;
+  cd -
+
+  #export LD_LIBRARY_PATH=/bmk/cms-patatrack/CMSSW_11_1_0_pre8_Patatrack/biglib/slc7_amd64_gcc820:/bmk/cms-patatrack/CMSSW_11_1_0_pre8_Patatrack/lib/slc7_amd64_gcc820:/bmk/cms-patatrack/CMSSW_11_1_0_pre8_Patatrack/external/slc7_amd64_gcc820/lib:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/cms/cmssw/CMSSW_11_1_0_pre8_Patatrack/biglib/slc7_amd64_gcc820:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/cms/cmssw/CMSSW_11_1_0_pre8_Patatrack/lib/slc7_amd64_gcc820:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/cms/cmssw/CMSSW_11_1_0_pre8_Patatrack/external/slc7_amd64_gcc820/lib:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/external/llvm/9.0.1-pfdnen/lib64:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/external/gcc/8.2.0-bcolbf/lib64:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/external/gcc/8.2.0-bcolbf/lib:/usr/local/nvidia/lib:/usr/local/nvidia/lib64
+  #export SRT_LD_LIBRARY_PATH_SCRAMRT=/bmk/cms-patatrack/CMSSW_11_1_0_pre8_Patatrack/biglib/slc7_amd64_gcc820:/bmk/cms-patatrack/CMSSW_11_1_0_pre8_Patatrack/lib/slc7_amd64_gcc820:/bmk/cms-patatrack/CMSSW_11_1_0_pre8_Patatrack/external/slc7_amd64_gcc820/lib:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/cms/cmssw/CMSSW_11_1_0_pre8_Patatrack/biglib/slc7_amd64_gcc820:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/cms/cmssw/CMSSW_11_1_0_pre8_Patatrack/lib/slc7_amd64_gcc820:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/cms/cmssw/CMSSW_11_1_0_pre8_Patatrack/external/slc7_amd64_gcc820/lib:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/external/llvm/9.0.1-pfdnen/lib64:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/external/gcc/8.2.0-bcolbf/lib64:/cvmfs/cms.cern.ch/slc7_amd64_gcc820/external/gcc/8.2.0-bcolbf/lib
 
+  # Configure WL copy
+  myecho "info about python"
+  python --version
+  which python
+  python -c 'import scipy; print(scipy.__path__)'
+  python -c 'from scipy import stats; import numpy as np; x=np.array([1,2,3]); y=np.array([1.1,2,2.9]); print(stats.linregress(x,y).slope)'
   return 0
 }