No Pineappl grids being produced by Madgraph

[ecole41]

I am trying to produce some Pineappl grids for the NLO p p > t t~ [QCD] process using madgraph, but am not getting any grids produced after launching.
I have set Pineappl = true in the run card and set the pineappl path to point to the pineappl config file, but after launching, I only get these files produced:
alllogs_0.html alllogs_1.html MADatNLO.gnuplot MADatNLO.HwU MADatNLO.pdf MADatNLO.ps res_0.txt res_1.txt run_10_tag_1_banner.txt RunMaterial.tar.gz summary.txt

and no grids.

I don't get any errors but I do get this warning:
WARNING: Compilation of the Subprocesses failed
which could possibly be causing an issue?

[felixhekhorn]

I'm not an mg5 expert so let me ping @ramonpeter (and maybe @scarlehoff ?)

In any case a relevant piece of information is: what was the exact madgraph version?

WARNING: Compilation of the Subprocesses failed

as far as I understand is magraph actually a compiler (i.e. it writes the true program on the fly) and this makes me think there might have been an issue already with madgraph itself, i.e. before the interface (e.g. some channels are missing). Did mg5 actually run? i.e. did it consume CPU or are the output files not empty?

[ecole41]

The version is 3.5.7.

Madgraph does run, I get plots after that follow expected distributions and I get HwU files produced. I've found that the WARNING: Compilation of the Subprocesses failed only shows after I change lhapdf = pdlabel in the run card, which you need for Pineappl to work.

[felixhekhorn]

Mmm then I've no more ideas and we need help from someone else 🙃

The version is 3.5.7.

just to say: this may or may not be the same problem as in #13

[scarlehoff]

@ramonpeter is the right person to ask. He was looking into upgrading the interface to the latest madgraph, I'm not sure what the status of that is.

But in any case, there are pinecards with TTB, does the problem persist if you use pinefarm as you run with this pinecard: https://github.com/NNPDF/pinecards/tree/master/CMS_TTB_13TEV_2L_TPT ?

[ramonpeter]

Hi @ecole41 ,
interesting, I have not seen this before. Would you mind sharing your exact process and run cards so I can try to reproduce the error/warning myself? And could you share the full logfile madgraph generated? Also, on what system are you running (iOS, Linux,..)?

@felixhekhorn, the error mentioned in #13 is of a different kind and is linked to custom cuts being implemented from outside.
This is due to a changes in the cut functions on the MG5 side and misalignment with the patches Christopher wrote.
This is not fixed yet, but I this is an error occuring on run time, while the compilation error happens at an earlier stage.

[ecole41]

Hello,

I have now managed to get grids produced with some help. I believe that it was a complier issue and some editing to madgraph was needed in MG5_aMC_v3_5_7/Template/NLO/SubProcesses:

qcd / 2 -> (unsigned int) (qcd / 2)
qed / 2 -> (unsigned int) (qed / 2)

Let me know if it would be helpful to send over the installation instructions which worked for me.

Thanks

[scarlehoff]

Thanks!

It would be very useful to add a "known issues" section to the Madgraph-pinefarm documentation indeed: https://pinefarm.readthedocs.io/en/latest/external/mg5.html which is here https://github.com/NNPDF/pinefarm/blob/main/docs/source/external/mg5.rst

[ramonpeter]

Hi @ecole41 ,
yes, it would indeed be helpful to know what your solution was.

Thanks

[ecole41]

These are the instructions that I followed to get the grids produced on my laptop. If I remember correctly, I also had to install the pineapple-cli

How to "properly" install Madgraph & all its friends on macOS arm64

Install MG5_aMC_v3_5_7, LHAPDF, and pineappl on macOS arm64:

0. Install conda

1. Create the conda environment and install the needed packages with

conda create -n mg5 python=3.9 six -y
conda activate mg5

Note: do not install any C++ or Fortran compiler in the environment, it is not a good solution, but they are not suited for the job (WEIRD).

2. Download and extract MG5_aMC_v3_5_7 with

wget https://launchpad.net/mg5amcnlo/3.0/3.6.x/+download/MG5_aMC_v3.5.7.tar.gz && tar -xf MG5_aMC_v3.5.7.tar.gz

3. Let's do it fancy (credits to Luca Mantani):

mkdir -p $CONDA_PREFIX/etc/conda/activate.d && echo "alias mg5=<path-to-madgraph>" > $CONDA_PREFIX/etc/conda/activate.d/env_vars.sh
mkdir -p $CONDA_PREFIX/etc/conda/deactivate.d && echo "unalias mg5" > $CONDA_PREFIX/etc/conda/deactivate.d/env_vars.sh

4. Download and extract LHAPDF-6.5.4 with

wget https://lhapdf.hepforge.org/downloads/LHAPDF-6.5.4.tar.gz && tar -xf LHAPDF-6.5.4.tar.gz

5. Install LHAPDF-6.5.4 with

cd LHAPDF-6.5.4
./configure --prefix=$CONDA_PREFIX --disable-python
make -j4
make install

6. Download and install pineappl-capi with

mkdir pineappl_capi
curl --proto '=https' --tlsv1.2 -sSf https://nnpdf.github.io/pineappl/install-capi.sh | sh -s -- --prefix <user-defined-path>

where <user-defined-path> is the one chosen by the user, and it must be written the absolute path.

7. Link this <user-defined-path> to /usr/local/lib with

sudo ln -s <user-defined-path>/lib/libpineappl_capi.0.8.7.dylib /usr/local/lib/libpineappl_capi.0.8.dylib

8. Fix the errors in the pineappl_interface.cc code in MG5_aMC_v3_5_7/Template/NLO/SubProcesses (which obviously MG5 does not tell you)

qcd / 2 -> (unsigned int) (qcd / 2)
qed / 2 -> (unsigned int) (qed / 2)

[felixhekhorn]

Thanks! I'd say this can go into a discussion here on the repo, so we can reference it

It would be very useful to add a "known issues" section to the Madgraph-pinefarm documentation indeed: https://pinefarm.readthedocs.io/en/latest/external/mg5.html which is here https://github.com/NNPDF/pinefarm/blob/main/docs/source/external/mg5.rst

also, as @scarlehoff said, we should add your point 8 (and only that) explicitly to our documentation (the other points are not directly related to the interface)