compile_7_6_4.readme.txt

The following are instructions on how to set up and compile the code on 
an sl7 cms workgroup server on lxplus or at DESY, 
with CMSSW_7_6_4 (2015 data and MC).
They will be complemented by instructions for other configurations.

  open a "fresh" xterm window on your sl7 machine at DESY or CERN:
xterm &
  or
ssh lxplus.cern.ch

once (1st time only, might only be needed later to access files for running):
---------------------
install grid certificate (userkey.pem) in .globus
set permissions to _r_______

every time:
-----------
   initialize cms grid proxy: 
   (can do later, might need to repeat later if proxy expired)
voms-proxy-init -voms cms
give passphrase

   at DESY only (no action needed on lxplus):
   initialize cmssw environment:
module use -a /afs/desy.de/group/cms/modulefiles
module load cmssw

once (first time only):
----------------------- 
   on the top directory in which you would like to install the code,
   (dot *not* mkdir the CMSSW directory beforehand) 
   create the CMSSW 7_6_4 environment:
cmsrel CMSSW_7_6_4 
   (ignore potential "Release ... is not available" error message)
   this will create the corresponding directory with subdirectories
   and reset the compiler version to slc7_amd64_gcc493

every time
----------
cd CMSSW_7_6_4/src

    make sure you have access rights to CERN git.
    (if you do not have them yet the git clone command will give an error)
    e.g., for access via your CERN kerberos token:
kinit "yourCERNusername"@CERN.CH

once (first time only)
----------------------
    in the src directory, set up .../CMSSW_7_6_4/src/NanoAOD/NanoAnalyzer/:
git clone https://:@gitlab.cern.ch:8443/cms-opendata/cms-opendata-nanoaodplus/nanoaodplus_v1.git NanoAOD/NanoAnalyzer

every time
----------
cd NanoAOD/NanoAnalyzer
   here you will now find the content of
   https://gitlab.cern.ch/cms-opendata/cms-opendata-nanoaodplus/nanoaodplus_v1
   technically, the NanoAnalyzer is a so-called EDAnalyzer
   (originally set up with mkdanlzr)

whenever you want to update the code to the latest version (not first time) 
---------------------------------------------------------------------------
git pull

   set the right environment
cmsenv

   compile for use on AOD:
scram b

   or instead compile for use on miniAOD:
scram b USER_CXXFLAGS="-DminiAOD"

For instructions how to run see run_readme.txt