lhapdf6 issues

Dear luca,

Hi, i am not an expert but i have installed the lhapdf6 and i got a problem like you and after googling i found that the MadGraph5 doesn't suuport the lhapdf6 and now i am using lhapdf5 (5.8.8) and it works fine.
I hope that this will help you.
Best regards.
Fethou.

Dear Fethou,

thanks for your answer. However, I managed to run amc@NLO + lhapdf6 on a linux machine, therefore I think it might be a problem of flags/compiler on my laptop, but I have no idea of how to configure things properly.

Best regards

Luca

ok, so which version of gfortran/gcc/g++ are you using??
and have you set the correct path to the lhapdf-config??

i asked you this question because if you are using the 4.8 version of compilers, you will get problems and this is from my own experience and after a long googling and i am also a linux user (ubuntu).

On the linux machine I have gfortran from gcc 4.9.2; however, this configuration on a linux machine works flawlessly, whereas I have problems on my laptop (I have a mac with osx 10.9) with gfortran from gcc (and clang as c++ compiler)

Dear Luca,

Hi, i never used the 4.9.2 version of the compilers and as i have explained you i am not an expert so i think that the MadGraph Team will help you better than me.

Good luck!!

Hi all,
so, as you have understood, linking lhapdf on a mac is quite a mess.
The reason is essentially that the clang compiler on the mac and the gnu fortran compiler are not much compatible one with the other.
The working solution i have found on my laptop is to replace the clang compiler with the gnu c/c++ compiler with the same version as gfortran.

When not linking lhapdf, we have managed to solve this compiler clash by adding these flags
-O -stdlib=libstdc++ -mmacosx-version-min=10.6
to the c/c++ files compiled with clang compilers.

It may be that compiling lhapdf6 (and also its dependencies: yaml/boost/...) with such flags may solve the issue, but i am not sure about that....

this is a bit the point of the situation.

Let me know what you think.
Cheers,

Marco

Hi Marco,

thanks for your reply. I tried to change the default c++ compiler in amc@nlo to g++-4.9 but I can't compile since I find problems with fastjet (which I compiled with g++-4.9) since I have always problems with lstdc:

Undefined symbols for architecture x86_64:
      "std::__1::__vector_base_common<true>::__throw_length_error() const", referenced from:
          __ZNSt3__16vectorIN7fastjet9PseudoJetENS_9allocatorIS2_EEE6assignIPS2_EENS_9enable_ifIXaasr21__is_forward_iteratorIT_EE5valuesr16is_constructibleIS2_NS_15iterator_traitsIS9_E9referenceEEE5valueEvE4typeES9_S9_ in fastjetfortran_madfks_full.o

and so on.

These problems disappear if I modify the flag lstdc++ with lc++ and I use clang, but with g++-4.9 I can't run (with or without lhapdf) no matter with flags I use.

Many thanks

Luca

Hi Luca,
note that, even if you install gcc4.9, it may be that gcc/g++ in your shell still points to clang (check with the version).

Also, after you have recompiled FJ with the new compiler, you need to set is a cpp_compiler in the madgraph interface.
Cheers,

Marco

On 16 Dec 2014, at 12:31, Luca <email address hidden> wrote:

> Question #259068 on MadGraph5_aMC@NLO changed:
> https://answers.launchpad.net/mg5amcnlo/+question/259068
>
> Status: Answered => Open
>
> Luca is still having a problem:
> Hi Marco,
>
> thanks for your reply. I tried to change the default c++ compiler in
> amc@nlo to g++-4.9 but I can't compile since I find problems with
> fastjet (which I compiled with g++-4.9) since I have always problems
> with lstdc:
>
> Undefined symbols for architecture x86_64:
> "std::__1::__vector_base_common<true>::__throw_length_error() const", referenced from:
> __ZNSt3__16vectorIN7fastjet9PseudoJetENS_9allocatorIS2_EEE6assignIPS2_EENS_9enable_ifIXaasr21__is_forward_iteratorIT_EE5valuesr16is_constructibleIS2_NS_15iterator_traitsIS9_E9referenceEEE5valueEvE4typeES9_S9_ in fastjetfortran_madfks_full.o
>
> and so on.
>
> These problems disappear if I modify the flag lstdc++ with lc++ and I
> use clang, but with g++-4.9 I can't run (with or without lhapdf) no
> matter with flags I use.
>
> Many thanks
>
> Luca
>
> --
> You received this question notification because you are a direct
> subscriber of the question.

Ciao Marco,

I made an alias g++=g++-4.9, so that whenever I call g++ it points to gcc (I checked with g++ -v). Then I re-extracted amc@NLO, I set fastjet in the shell to the recompiled one, and I set the c++ compiler in mg5_configuration to g++-4.9.

Thanks,

Luca

Ciao Marco,

I don't know if it was clear from my previous message, but I did those things and the lstdc problems still appear.

Many thanks

Luca

Dear aMC@NLO authors,

I'm seeing a similar bug. For me this happens on linux system with gcc 4.8. Moreover, this is process specific. I don't see it for ttbarW but it pops out in ttbarttbar. I'm also using MG 2.2.2 and LHAPDF 6.1.4.

cheers,
Wojciech

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