NLO process always gives lhapdf error in the output stage

[Sung Hak Lim]

Dear MG5_aMC@NLO team,

I'm trying to use NLO calculation with MG5_aMC@NLO but I always got this warning even though I properly installed LHAPDF6.

MG5 version: 2.5.4

INFO: The value for lhapdf in the current configuration does not correspond to a valid executable.
Please set it correctly either in input/mg5_configuration or with "set lhapdf /path/to/lhapdf-config" and regenrate the process.
To avoid regeneration, edit the /home/starlight/mgoutput/stop3/Cards/amcatnlo_configuration.txt file.
Note that you can still compile and run aMC@NLO with the built-in PDFs

It looks that the error came from [MG5]/madgraph/iolibs/export_fks.py .

In line 734:
try:
  res = misc.call([self.options['lhapdf'], '--version'] \
              stdout=subprocess.PIPE, stderr=subprocess.PIPE)
It seems self.options always throws expection because it is not defined in object ProcessOptimizedExporterFortranFKS.

It seems that correct form is

try:
  res = misc.call([mg5options['lhapdf'], '--version'] \
              stdout=subprocess.PIPE, stderr=subprocess.PIPE)

Is this a serious bug or just a notification bug while internals working well?

Have a nice day!

Best wishes,
Sung Hak Lim

[Olivier Mattelaer (olivier-mattelaer)]

Hi,

Thanks a lot for spotting this and report to us (sorry for the slow reply, I was in paternity leave --actually I'm still in--).

This is indeed the correct fix. In any case, this is just indeed a notification bug with everything working correcly.

Thanks again,

Olivier