compiling on lxplus.cern.ch (slc6, gcc4.8.1)

[Andrea Giammanco]

Dear developers,
today I downloaded the Delphes 3.1.2 tarball (​http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.1.2.tar.gz) on lxplus.cern.ch (scientific linux 6), and I tried to compile with "make". My gcc version is 4.8.1 and of course I am using my CMS account.
In addition to several warnings (variables declared but not used, comparisons between signed and unsigned, etc.) I get a compilation failure:

(...)

Compiling modules/PileUpMergerPythia8.cc
Compiling external/tcl/tclObj.c

modules/PileUpMergerPythia8.cc:25:20: fatal error: Pythia.h: No such file or directory

#include "Pythia.h"

compilation terminated.
make: * [tmp/modules/PileUpMergerPythia8.o] Error 1

If I repeat the very same actions on our ingrid-ui1, instead, everything fine.
Do you know the cause of this different behavior? Any advice on how to work around it?
(Running Delphes on lxplus would make my life a bit easier.)

[Pavel Demin]

Hi Andrea,

could you, please provide a list of command that you are using to setup your environment variables on lxplus.cern.ch? Are you using just GCC+ROOT or complete CMSSW environment?

Cheers,

Pavel

[Pavel Demin]

Here is a list of commands I use to reproduce the problem:

export SCRAM_ARCH=slc6_amd64_gcc481
export BUILD_ARCH=slc6_amd64_gcc481
source /cvmfs/cms.cern.ch/cmsset_default.sh
scram project CMSSW CMSSW_7_1_0_pre9
cd CMSSW_7_1_0_pre9
wget http://cp3.irmp.ucl.ac.be/downloads/Delphes-3.0.12.tar.gz
tar -zxf Delphes-3.1.2.tar.gz
cd Delphes-3.1.2
cmsenv
make -j 8

[Pavel Demin]

Looks like the path to the Pythia8 include files changed in the CMSSW installation.

In older version of CMSSW it was $(PYTHIA8DATA)/../include, in more recent version it's $(PYTHIA8DATA)/../include/Pythia8.

I propose to fix it by replacing

#include "Pythia.h"

with

#include "Pythia8/Pythia.h"

in modules/PileUpMergerPythia8.cc and in readers/DelphesPythia8.cpp.

Actually, it was already suggested in ticket #288.

So, Andrea, you can apply this fix manually to your current Delphes version and we'll include it in the next Delphes release.