set() got multiple values for argument 'changeifuserset'

[Andrea Valassi]

Hi, using the latest 2.9.2, I am doing some very basic things as a beginner. I created an ee to mumu process. Without gridpack, all went ok. Then I tried to only change the setting to get a gridpack, and I got the following error:

Command "generate_events run_01" interrupted with error:
TypeError : set() got multiple values for argument 'changeifuserset'
Please report this bug on https://bugs.launchpad.net/mg5amcnlo
More information is found in 'ME5_debug'.
Please attach this file to your report.

The error happened when I typed launch and then after the first enter to accept my run card I think.

I am attaching the ME5_debug file.

Thanks!
Andrea

[Andrea Valassi (andrea-valassi)]

By the way, I tested that this issue only happens with python3.8. With the same runcards on python 2.7, I do not get this error.

[Olivier Mattelaer (olivier-mattelaer)]

Thanks Andrea,

Indeed we have a stupid syntax error which occur only for gridpack and python3.
The most stupid point is that such line is 100% useless.
So removing such line is enough.
you will have the patch here:

https://bazaar.launchpad.net/~maddevelopers/mg5amcnlo/2.9.3/revision/307

Thanks a lot for the bug report.

Olivier

[Andrea Valassi (andrea-valassi)]

Hi Olivier, thanks a lot! I confirm this fixed the issue.
(I then later got a different issue, but I will report that separately).
Cheers Andrea