PYTHIA8 does not work @NLO

Hi,
I forgot to mention that pythia 8 is running fine for leading order processes . i.e the same process without [QCD] is working fine.

Also i tried using pythia8 installed externally in my computer ,by providing the path in the configuration file. In this case also the leading order process is working fine , but the next to leading order process generated following the same procedure discussed above is giving following error...

INFO:
   --------------------------------------------------------------
      Summary:
      Process p p > t t~ [QCD]
      Run at p-p collider (6500.0 + 6500.0 GeV)
      Number of events generated: 10000
      Total cross section: 6.825e+02 +- 4.3e+00 pb
   --------------------------------------------------------------
      Scale variation (computed from LHE events):
          Dynamical_scale_choice -1 (envelope of 9 values):
              6.873e+02 pb +10.6% -12.2%
   --------------------------------------------------------------

INFO: The /home/rameswar.s/Desktop/softwares/MG5_aMC_v3_3_2/mytest_NLO1/Events/run_01/events.lhe.gz file has been generated.

INFO: Events generated
reweight -from_cards
decay_events -from_cards
INFO: Preparing MCatNLO run
INFO: Using LHAPDF v6.3.0 interface for PDFs
INFO: Compiling MCatNLO for PYTHIA8...
INFO: ... done
INFO: Showering events...
INFO: (Running in /home/rameswar.s/Desktop/softwares/MG5_aMC_v3_3_2/mytest_NLO1/MCatNLO/RUN_PYTHIA8_1)
INFO: Idle: 1, Running: 0, Completed: 0 [ current time: 12h33 ]
mv: cannot stat 'Pythia8.hep': No such file or directory
gzip: events.hepmc: No such file or directory
INFO: Idle: 0, Running: 0, Completed: 1 [ 0.24s ]
INFO: Idle: 0, Running: 0, Completed: 0 [ current time: 12h33 ]
Error detected in "launch auto "
write debug file /home/rameswar.s/Desktop/softwares/MG5_aMC_v3_3_2/mytest_NLO1/run_01_tag_1_debug.log
If you need help with this issue, please, contact us on https://answers.launchpad.net/mg5amcnlo
str : No file has been generated, an error occurred. More information in /home/rameswar.s/Desktop/softwares/MG5_aMC_v3_3_2/amcatnlo_run.log
quit
INFO:
MG5_aMC>
Please look into the problem.

best,
Rameswar

This sounds a compilation ordering issue,
I did fixed a lot of them within 3.4.0 and I just released the Release Candidate.
So Maybe you can check if the problem is fixed, I will anyway assign some time to look at this. (sorry to not have look earlier I had an email issue and realize it only now) --the issue is that the bug is platform dependent and that I typically do not reproduce those--)

Thanks,

Olivier

Hi,

I actually do reproduce the error (with 3.4.0) so clearly this is not fixed in that release candidate.

Cheers,

Olivier

Actually this is nothing new and the workaround is well know.
you have to put HwU.o first.

This is actually mention in the shower_card.dat:

ANALYSE = # User's analysis and histogramming
                                 # routines (please use .o as extension
                                 # and use spaces to separate files).
                                 # If the HwU.o files has to be linked,
                                 # it should be put *first*.

Cheers,

Olivier

Hi Olivier,
 Thanks for your response....I tried generating p p > t t~ [QCD] with 3.4.0 , keeping the analysis option blank (i.e. i want to generate the hepmc file without generating any histograms).... But, I am getting the same compilation error... Any suggestions???

 Best,
Rameswar

Here is the log file....

launch auto
Traceback (most recent call last):
  File "/home/rama/anaconda3/lib/python3.8/shutil.py", line 788, in move
    os.rename(src, real_dst)
FileNotFoundError: [Errno 2] No such file or directory: '/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/trial/MCatNLO/RUN_PYTHIA8_1/events.hepmc.gz' -> '/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/trial/Events/run_01/events_PYTHIA8_0.hepmc.gz'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/madgraph/interface/amcatnlo_run_interface.py", line 4090, in run_mcatnlo
    files.mv(os.path.join(rundir, 'events.%s.gz' % ext), hep_file)
  File "/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/madgraph/iolibs/files.py", line 186, in mv
    shutil.move(path1, path2)
  File "/home/rama/anaconda3/lib/python3.8/shutil.py", line 802, in move
    copy_function(src, real_dst)
  File "/home/rama/anaconda3/lib/python3.8/shutil.py", line 432, in copy2
    copyfile(src, dst, follow_symlinks=follow_symlinks)
  File "/home/rama/anaconda3/lib/python3.8/shutil.py", line 261, in copyfile
    with open(src, 'rb') as fsrc, open(dst, 'wb') as fdst:
FileNotFoundError: [Errno 2] No such file or directory: '/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/trial/MCatNLO/RUN_PYTHIA8_1/events.hepmc.gz'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/madgraph/interface/extended_cmd.py", line 1544, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/madgraph/interface/amcatnlo_run_interface.py", line 1805, in do_launch
    self.run_mcatnlo(evt_file, options)
  File "/home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/madgraph/interface/amcatnlo_run_interface.py", line 4106, in run_mcatnlo
    raise aMCatNLOError('No file has been generated, an error occurred.'+\
madgraph.interface.amcatnlo_run_interface.aMCatNLOError: No file has been generated, an error occurred. More information in /home/rama/HEP_Softwares/MG5_aMC_v3_4_0_RC/amcatnlo_run.log

Hi Olivier,
I had the same error as in comment #1 before, but it works with 3.4.0, so it seems to be fixed at least for my setup.
Best,
Manuel

Hi Olivier,
 The problem got solved in 3.4.0... The problem was with lhapdf6.... I re-installed it and now everything is working fine...
Thanks for your time...

Best,
Rameswar

Thanks Olivier Mattelaer, that solved my question.