MadGraph5_aMC@NLO

pythia8 problem

Asked by Luca

Hi,

I recently installed madgraph5_amc@nlo on a new machine, but it seems that something is wrong with the latest installer of pythia8 (which I installed using install pythia8). I cannot run the shower as I get errors like

./aj/Events/run_01/PY8_parallelization/split_18/PY8_log.txt: PYTHIA Abort from Pythia::Pythia: unmatched version numbers : in code 8.240 but in XML 8.223

Thanks,
Luca

Question information

Language:
English Edit question
Status:
Solved
For:
MadGraph5_aMC@NLO Edit question
Assignee:
No assignee Edit question
Solved by:
Luca
Solved:
Last query:
Last reply:
Revision history for this message
Olivier Mattelaer (olivier-mattelaer) said : 		#1

Hi,

I would suggest to contact Pythia8 author for that issue.
It is not the first time that I heard about the issue (looks like an old issue present in also different code):
Did you read any of the following thread?
https://bugs.launchpad.net/bugs/1649725
https://answers.launchpad.net/mg5amcnlo/+question/670673
https://root-forum.cern.ch/t/unmatched-version-numbers-constructur-initialization/17730

according to such thread you have a environment variable PYTHIA8DATA
which point to another version of Pythia8:
to solve this you have to overwritte that variable to your local PY8 one:

set PYTHIA8DATA to MG5_dir/HEPTools/pythia8/share/Pythia8/xmldoc

Cheers,

Olivier

Revision history for this message
Luca (r8li) said : 		#2

Hi Olivier,
Thanks for the answer. I am not sure if that was the case as I tried to configure mg5+pythia on a new account on a cluster, where there was no previous installation of pythia as far as I can tell. Eventually I managed to solve the problem by installing pythia externally and linking the external installation to mg5; this seemed to solve the issue. Thanks for pointing out to me the threads!
Luca