issue with configuration file

[Olivier Mattelaer]

I'm using MG5 v3.5.3. I have manually installed pythia8 somewhere else and input the path in the configuration file. Then successfully installed the mg5amc_py8_interface.

Then I tried to generate some random process, e.g. p p > t t~. Then output, then launch. There is no shower/hadronization option.

Some output during the launching process:

INFO: load configuration from /Users/quarkquartet/Work/DM-enc/tt-coupling/bkg_tt/Cards/me5_configuration.txt
INFO: load configuration from /Users/quarkquartet/Work/MG5_aMC_v3_5_3/input/mg5_configuration.txt
INFO: load configuration from /Users/quarkquartet/Work/DM-enc/tt-coupling/bkg_tt/Cards/me5_configuration.txt
generate_events run_01
The following switches determine which programs are run:
/=================== Description ===================|============= values ==============|======== other options ========\
| 1. Choose the shower/hadronization program | shower = Not Avail. | Please install module |
| 2. Choose the detector simulation program | detector = Not Avail. | Please install module |
| 3. Choose an analysis package (plot/convert) | analysis = Not Avail. | Please install module |
| 4. Decay onshell particles | madspin = OFF | ON|onshell|full |
| 5. Add weights to events for new hypp. | reweight = OFF | ON |
\=======================================================================================================================/

I notice that the configuration file in the output directory is 'me5_configuration', is this a typo?

The configuration file in the output directory, however, is indeed 'me5_configuration.txt'. I can find it. But the pythia8 path and mg5amc_py8_interface path are both not properly configured. However those are properly configured in the MG5path/input/mg5_configuration.txt file.

Is there a bug in this output?

[Olivier Mattelaer (olivier-mattelaer)]

Hi,

I have convert your question to a bug report,
This will allow you to attach file.
Could you attach your
input/mg5_configuration.txt
and your
Cards/me5_configuration.txt

My current bet on your issue is that your Cards/me5_configuration.txt
is overwritting your pythia8 path (and it has precedence).
If that's the case the question is how did you generate the Process?
(and how pythia8 was configure at the time)

Cheers,

Olivier

[Isaac Wang (isaac95)]

Thank you Olivier.

I'm doing the following test with the configuration file attached: completely reinstall the MG5 and set paths. It seems that the attachment only allows for one file at a time. I'll upload one by one.

I do:
```
set pythia8_path $HOME/Work/local/pythia8/bin/pythia8-config
set lhapdf $HOME/Work/local/lhapdf6-nopy/bin/lhapdf-config
set fastjet $HOME/Work/local/fastjet3/bin/fastjet-config
```

Then I do

```
install mg5amc_py8_interface
```

I got:
```
A problem occured during the installation of 'mg5amc_py8_interface'.
Content of the installation log file '/Users/quarkquartet/Work/MG5_aMC_v3_5_3/HEPTools/MG5aMC_PY8_interface/mg5amc_py8_interface_install.log':

Error, could not retrieve Pythia8 version using script 'get_pythia8_version.py'. Check it.

Command "install mg5amc_py8_interface" interrupted with error:
InvalidCmd : Installation of mg5amc_py8_interface failed.
```
The log file is attached.
Then I quit MG5 and restarted, installed this mg5py8 interface again, and installation was successful this time.

I do a test to generate event:

```
generate p p > t t~
output ~/Work/test/testMG5
launch
```

It shows `not available` in the shower/hadronization option.

The MG5path/input/mg5_configuration.txt is attached. I did not do anything except for the above steps.

[Isaac Wang (isaac95)]

The mg5_py8_interface installation log file for the first time (which reports error that py8 version cannot be found) is here.

[Isaac Wang (isaac95)]

The `testMG5/Cards/me5_configuration.txt` is here.

[Olivier Mattelaer (olivier-mattelaer)]

Sorry for the long delay.

Maybe the issue is that you need to specify pythia8_path like this:
set pythia8_path $HOME/Work/local/pythia8/

Anyway, I have investigate what the code
get_pythia8_version.py
is doing

first it is looking at the file
share/Pythia8/xmldoc/Version.xml
(that it likely finds) and check for the version number inside.
If that does not work, it compiles a small cpp code versus pythia8 to get back the version.
Could you check the content of the Version.xml file?

Cheers,

Olivier

[Isaac Wang (isaac95)]

Hi Olivier,

Thank you for your comment. I have already posted a comment in the original 'answer' post.

I think the problem is that the pythia_path should not point to the pythia-config file, but just point to the folder of the whole pythia installation. Changing this can solve the problem.