Hi Keping,

I guess setting dl in the shower_card without changing the
makefiles should be enough. Anyway, good that this part of
the problem is solved.

For the other part, this seem to be related to something
going wrong during the shower itself, i.e. could you confirm
this error message is issued after Pythia8 has started
showering?

In this case, you could go inside RUN_PYTHIA8_3 and check
mcatnlo_run.log, which is the event record, and there you
should find some more indication. It would be useful if
you could attach mcatnlo_run.log and shower card.dat to
your next post both.

Another suggestion is to use version 2.3.3 of the MG5_aMC
code, since there, for example, the dl problem is already
solved.
Moreover, it is not necessary to set the hepmc path in
the mg5 configuration file, as pythia knows it already.
Finally, just to be sure, is the first line of your event
file equal to the following?
<LesHouchesEvents version="3.0”>

Cheers,
Paolo


On 19 Nov 2015, at 06:15, Keping Xie <email address hidden> wrote:

> Hi Paolo,
> 
> As you suggest, I edit the shower_card.dat as
> EXTRALIBS = dl
> 
> And I also tried the Luca's suggestion, add the flag "-ldl" in Makefile and Makefile_hep.
> It seems that the library problem is solved, but another problem appear, showing as 
> IOError: [Errno 2] No such file or directory: '/users/kepingx/MG5_aMC_v2_3_2_2/pp_bbx_QCD/MCatNLO/RUN_PYTHIA8_3/events.hepmc.gz'
> 
> I have set the path to pythia8 and hepmc in the
> "input/mg5_configuration.txt".
> 
> So, what do you think of this error?
> 
> Best regards!
> Keping
> 
> ** Attachment added: "run_24_tag_1_debug.log"
>   https://bugs.launchpad.net/mg5amcnlo/+bug/1517186/+attachment/4521704/+files/run_24_tag_1_debug.log
> 
> -- 
> You received this bug notification because you are a bug assignee.
> https://bugs.launchpad.net/bugs/1517186
> 
> Title:
>  pythia8 interface
> 
> Status in MadGraph5_aMC@NLO:
>  New
> 
> Bug description:
>  I want to do the calculation of "p p > b b~ [QCD]", and interface MadGraph with Pythia8 to get the B-meson information.
>  I have installed pythia8 successfully configured with HepMC2, LHAPDF6, ROOT, Fastjet3.
> 
>  However, when I launch pp_bbx_QCD, and choose 
>    PYTHIA8       =  parton_shower
> 
>  It gives me error message:
>  /users/kepingx/share/pythia8/lib/libpythia8.a(PartonDistributions.o): In function `Pythia8::LHAPDF::symbol(std::string)':
>  PartonDistributions.cc:(.text+0xe6c0): undefined reference to `dlerror'
>  PartonDistributions.cc:(.text+0xe6cc): undefined reference to `dlsym'
>  PartonDistributions.cc:(.text+0xe6d4): undefined refePythia8 compilation did not succeed, exiting
>  ext+0xe782): undefined reference to `dlerror'
>  PartonDistributions.cc:(.text+0xe7ad): undefined reference to `dlopen'
>  PartonDistributions.cc:(.text+0xe7b5): undefined reference to `dlerror'
>  /users/kepingx/share/pythia8/lib/libpythia8.a(PartonDistributions.o): In function `Pythia8::LHAPDF::~LHAPDF()':
>  PartonDistributions.cc:(.text+0xfaea): undefined reference to `dlclose'
>  PartonDistributions.cc:(.text+0xfaf1): undefined reference to `dlerror'
>  collect2: error: ld returned 1 exit status
>  make: *** [Pythia82] Error 1
> 
>  So, how can interface MadGraph_aMC@NLO correctly with Pythia8?
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/mg5amcnlo/+bug/1517186/+subscriptions