So this a bug affecting only the computation of the auto-width.
This affects computation of width for 
1>3 and 1>4 with identical particles in the final state.

So for the model/processes affected this obviously only impact processes where 
1>2 body decay are not the main bluk of the width (which should be most of the model obviously)

Cheers,

Olivier


> On 3 Nov 2020, at 22:29, Hannes <email address hidden> wrote:
> 
> Hi Olivier,
> 
> thanks. Final question: what is the extend of the bug in the older
> releases? Which processes, models, or use cases would be affected by it?
> 
> Cheers,
> Hannes
> 
> -- 
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1902788
> 
> Title:
>  issue with 4 body decay and identical particles
> 
> Status in MadGraph5_aMC@NLO:
>  Confirmed
> 
> Bug description:
>  Hi,
> 
>  MG5_aMC is crashing when automatically calculation widths using the
>  Pseudoscalar_2HDM model (*):
> 
>  Command "generate_events run_01" interrupted in sub-command:
>  "set max_npoint_for_channel 0" with error:
>  KeyError : 2
> 
>  Versions 2.8.1 and 2.8.2 seem to be affected, the same thing used to work in 2.6.7.
>  We are using python2.
> 
>  We are essentially calling:
>> import model Pseudoscalar_2HDM-bbMET_5FS --modelname
>> generate p p > t t~ #doesn't really matter
>> output test
>> launch
>> done
>> set Wh1 auto
>> set Wh2 auto
>> set Wh3 auto
>> set Wh4 auto
>> done
> 
>  I've copied the MG5_debug at the bottom of this message (there is also
>  a ME5_debug file which is empty).
> 
>  Any help with this would be appreciated.
> 
>  Cheers,
>  Hannes
> 
>  *) https://github.com/LHC-DMWG/model-
>  repository/tree/master/models/Pseudoscalar_2HDM
> 
>  ---MG5_debug.log---
> 
>  #************************************************************
>  #*                     MadGraph5_aMC@NLO                    *
>  #*                                                          *
>  #*                *                       *                 *
>  #*                  *        * *        *                   *
>  #*                    * * * * 5 * * * *                     *
>  #*                  *        * *        *                   *
>  #*                *                       *                 *
>  #*                                                          *
>  #*                                                          *
>  #*         VERSION 2.8.2                 2020-10-30         *
>  #*                                                          *
>  #*    The MadGraph5_aMC@NLO Development Team - Find us at   *
>  #*    https://server06.fynu.ucl.ac.be/projects/madgraph     *
>  #*                                                          *
>  #************************************************************
>  #*                                                          *
>  #*               Command File for MadGraph5_aMC@NLO         *
>  #*                                                          *
>  #*     run as ./bin/mg5_aMC  filename                       *
>  #*                                                          *
>  #************************************************************
>  set group_subprocesses Auto
>  set ignore_six_quark_processes False
>  set max_t_for_channel 99
>  set loop_optimized_output True
>  set low_mem_multicore_nlo_generation False
>  set default_unset_couplings 99
>  set zerowidth_tchannel True
>  set loop_color_flows False
>  set gauge unitary
>  set complex_mass_scheme False
>  set max_npoint_for_channel 0
>  Traceback (most recent call last):
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1541, in onecmd
>      return self.onecmd_orig(line, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1490, in onecmd_orig
>      return func(arg, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/madevent_interface.py", line 2463, in do_generate_events
>      switch_mode = self.ask_run_configuration(mode, args)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/madevent_interface.py", line 6234, in ask_run_configuration
>      self.ask_edit_cards(cards, plot=False, first_cmd=first_cmd)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/common_run_interface.py", line 982, in ask_edit_cards
>      banner=banner)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/common_run_interface.py", line 1054, in ask_edit_card_static
>      cards=cards, mode=mode, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1150, in ask
>      fct=question_instance, fct_timeout=fct_timeout)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1755, in timed_input
>      result = fct(question)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 2118, in __call__
>      return self.cmdloop()
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 2286, in cmdloop
>      super(SmartQuestion,self).cmdloop(intro)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 179, in cmdloop
>      stop = self.postcmd(stop, line)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/common_run_interface.py", line 6081, in postcmd
>      self.do_update('dependent', timer=20)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/common_run_interface.py", line 6127, in do_update
>      self.do_compute_widths('')
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/common_run_interface.py", line 6498, in do_compute_widths
>      out = self.mother_interface.do_compute_widths(line)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/common_run_interface.py", line 2318, in do_compute_widths
>      out = cmd.exec_cmd(line, model=opts['model'])
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1570, in exec_cmd
>      stop = Cmd.onecmd_orig(current_interface, line, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1490, in onecmd_orig
>      return func(arg, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/master_interface.py", line 346, in do_compute_widths
>      return self.cmd.do_compute_widths(self, *args, **opts)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/madgraph_interface.py", line 8500, in do_compute_widths
>      self.exec_cmd('output madevent %s -f' % decay_dir,child=False)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1570, in exec_cmd
>      stop = Cmd.onecmd_orig(current_interface, line, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/extended_cmd.py", line 1490, in onecmd_orig
>      return func(arg, **opt)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/master_interface.py", line 299, in do_output
>      self.cmd.do_output(self, line, *args, **opts)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/madgraph_interface.py", line 7993, in do_output
>      self.export(nojpeg, main_file_name, group_processes, args)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/master_interface.py", line 313, in export
>      return self.cmd.export(self, *args, **opts)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/madgraph_interface.py", line 8123, in export
>      ndiags, cpu_time = generate_matrix_elements(self,group_processes)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/interface/madgraph_interface.py", line 8105, in generate_matrix_elements
>      matrix_element_opts=mode)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/core/helas_objects.py", line 5588, in __init__
>      compute_loop_nc = compute_loop_nc))
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/core/helas_objects.py", line 5815, in generate_matrix_elements
>      amplitude_tag = IdentifyMETag.create_tag(amplitude)
>    File "/home/hmildner/HEP/MG5_aMC_v2_8_2/madgraph/core/helas_objects.py", line 117, in create_tag
>      for p in sorted_tags[1:]]
>  KeyError: 2
>                            MadGraph5_aMC@NLO Options    
>                            ----------------    
>          complex_mass_scheme 	:	False
>      default_unset_couplings 	:	99 (user set)
>                        gauge 	:	unitary
>           group_subprocesses 	:	Auto
>    ignore_six_quark_processes 	:	False
>             loop_color_flows 	:	False
>        loop_optimized_output 	:	True
>    low_mem_multicore_nlo_generation 	:	False
>       max_npoint_for_channel 	:	0 (user set)
>            max_t_for_channel 	:	99 (user set)
>                 stdout_level 	:	20 (user set)
>           zerowidth_tchannel 	:	True
> 
>                           MadEvent Options    
>                            ----------------    
>       automatic_html_opening 	:	False (user set)
>                      nb_core 	:	4 (user set)
>          notification_center 	:	True
>                     run_mode 	:	2
> 
>                        Configuration Options    
>                        ---------------------    
>                          OLP 	:	MadLoop
>                      amcfast 	:	amcfast-config
>                     applgrid 	:	applgrid-config
>                  auto_update 	:	7 (user set)
>           cluster_local_path 	:	None
>             cluster_nb_retry 	:	1
>                cluster_queue 	:	None (user set)
>           cluster_retry_wait 	:	300
>                 cluster_size 	:	100
>        cluster_status_update 	:	(600, 30)
>            cluster_temp_path 	:	None
>                 cluster_type 	:	condor
>                      collier 	:	./HEPTools/lib
>                 cpp_compiler 	:	None
>               crash_on_error 	:	False
>                 delphes_path 	:	None (user set)
>                   eps_viewer 	:	None
>          exrootanalysis_path 	:	None (user set)
>                f2py_compiler 	:	None
>            f2py_compiler_py2 	:	None
>            f2py_compiler_py3 	:	None
>                      fastjet 	:	fastjet-config
>             fortran_compiler 	:	None
>                        golem 	:	None (user set)
>                   hepmc_path 	:	None (user set)
>                    hwpp_path 	:	None (user set)
>                       lhapdf 	:	lhapdf-config
>                   lhapdf_py2 	:	None
>                   lhapdf_py3 	:	None
>            madanalysis5_path 	:	None (user set)
>             madanalysis_path 	:	None (user set)
>    mg5amc_py8_interface_path 	:	None (user set)
>                        ninja 	:	./HEPTools/lib
>          output_dependencies 	:	external
>              pythia-pgs_path 	:	None (user set)
>                 pythia8_path 	:	None (user set)
>                      samurai 	:	None
>                 syscalc_path 	:	None (user set)
>                      td_path 	:	None (user set)
>                  text_editor 	:	emacs (user set)
>                  thepeg_path 	:	None (user set)
>                      timeout 	:	60
>                  web_browser 	:	None
> 
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