Did you follow the instruction of this page?

https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Installation <https://cp3.irmp.ucl.ac.be/projects/madgraph/wiki/Installation>

Cheers,

Olivier

> On 17 Oct 2020, at 12:46, Diogo Franco Graça Pires <email address hidden> wrote:
> 
> Public bug reported:
> 
> Hi!
> 
> I am on a Mac and just downloaded MadGraph and started the tutorial. 
> While on the 3rd step "c) How to run the MadEvent output", I encountered this error:
> 
> ******************
>> done
> INFO: Update the dependent parameter of the param_card.dat 
> Generating 10000 events with run name run_01
> survey  run_01 
> INFO: compile directory 
> compile Source Directory
> Using random number seed offset = 21
> INFO: Running Survey 
> Creating Jobs
> Working on SubProcesses
> INFO:     P1_gg_ttx  
> Error detected in "generate_events run_01"
> write debug file /Users/diogopires/Desktop/MG5_aMC_v2_8_1/MY_FIRST_MG5_RUN/run_01_tag_1_debug.log 
> If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
> str : A compilation Error occurs when trying to compile /Users/diogopires/Desktop/MG5_aMC_v2_8_1/MY_FIRST_MG5_RUN/SubProcesses/P1_gg_ttx.
> 	The compilation fails with the following output message:
> 	    gfortran -O -w -fbounds-check -fPIC -ffixed-line-length-132 -w -c symmetry.f -I../../Source/
> 	    gfortran -O -w -fbounds-check -fPIC -ffixed-line-length-132 -w -c idenparts.f -I../../Source/
> 	    gfortran -o gensym symmetry.o idenparts.o  -L../../lib/ -lmodel -lgeneric -lpdf  -lc++ -mmacosx-version-min=10.8
> 	    ld: library not found for -lc++
> 	    collect2: error: ld returned 1 exit status
> 	    make: *** [gensym] Error 1
> 	    
> 	Please try to fix this compilations issue and retry.
> 	Help might be found at https://answers.launchpad.net/mg5amcnlo.
> 	If you think that this is a bug, you can report this at https://bugs.launchpad.net/mg5amcnlo
> quit
> ******************
> 
> How can proceed in order to solve this?
> 
> Thank you for your help!
> 
> Diogo
> 
> ** Affects: mg5amcnlo
>     Importance: Undecided
>         Status: New
> 
> -- 
> You received this bug notification because you are subscribed to
> MadGraph5_aMC@NLO.
> https://bugs.launchpad.net/bugs/1900239
> 
> Title:
>  MadGraph Tutorial "run output" Error
> 
> Status in MadGraph5_aMC@NLO:
>  New
> 
> Bug description:
>  Hi!
> 
>  I am on a Mac and just downloaded MadGraph and started the tutorial. 
>  While on the 3rd step "c) How to run the MadEvent output", I encountered this error:
> 
>  ******************
>> done
>  INFO: Update the dependent parameter of the param_card.dat 
>  Generating 10000 events with run name run_01
>  survey  run_01 
>  INFO: compile directory 
>  compile Source Directory
>  Using random number seed offset = 21
>  INFO: Running Survey 
>  Creating Jobs
>  Working on SubProcesses
>  INFO:     P1_gg_ttx  
>  Error detected in "generate_events run_01"
>  write debug file /Users/diogopires/Desktop/MG5_aMC_v2_8_1/MY_FIRST_MG5_RUN/run_01_tag_1_debug.log 
>  If you need help with this issue please contact us on https://answers.launchpad.net/mg5amcnlo
>  str : A compilation Error occurs when trying to compile /Users/diogopires/Desktop/MG5_aMC_v2_8_1/MY_FIRST_MG5_RUN/SubProcesses/P1_gg_ttx.
>  	The compilation fails with the following output message:
>  	    gfortran -O -w -fbounds-check -fPIC -ffixed-line-length-132 -w -c symmetry.f -I../../Source/
>  	    gfortran -O -w -fbounds-check -fPIC -ffixed-line-length-132 -w -c idenparts.f -I../../Source/
>  	    gfortran -o gensym symmetry.o idenparts.o  -L../../lib/ -lmodel -lgeneric -lpdf  -lc++ -mmacosx-version-min=10.8
>  	    ld: library not found for -lc++
>  	    collect2: error: ld returned 1 exit status
>  	    make: *** [gensym] Error 1
>  	    
>  	Please try to fix this compilations issue and retry.
>  	Help might be found at https://answers.launchpad.net/mg5amcnlo.
>  	If you think that this is a bug, you can report this at https://bugs.launchpad.net/mg5amcnlo
>  quit
>  ******************
> 
>  How can proceed in order to solve this?
> 
>  Thank you for your help!
> 
>  Diogo
> 
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/mg5amcnlo/+bug/1900239/+subscriptions