MG5_aMC_v3_4_2, Cuttools does not compile with Python 3.9

Dear experts,

I do the following:

Download MG5_aMC_v3_4_2
tar xafv MG5_aMC_v3_4_2*

python3.9 ./bin/mg5_aMC
install fastjet
install lhapdf6

import model loop_sm-no_b_mass
generate p p > t t~ a [QCD]
output test

The compilation of Cuttools fails then with the following errors.
Could you please advise what is going wrong?

Traceback (most recent call last):
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/interface/extended_cmd.py", line 1544, in onecmd
    return self.onecmd_orig(line, **opt)
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/interface/extended_cmd.py", line 1493, in onecmd_orig
    return func(arg, **opt)
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/interface/master_interface.py", line 299, in do_output
    self.cmd.do_output(self, line, *args, **opts)
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/interface/amcatnlo_interface.py", line 740, in do_output
    self._curr_exporter.copy_fkstemplate(self._curr_model)
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/iolibs/export_fks.py", line 4067, in copy_fkstemplate
    self.link_CutTools(dir_path)
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/loop/loop_exporters.py", line 168, in link_CutTools
    misc.compile(cwd=self.cuttools_dir, job_specs = False)
  File "/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/madgraph/various/misc.py", line 558, in compile
    raise MadGraph5Error(error_text)
madgraph.MadGraph5Error: A compilation Error occurs when trying to compile /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/vendor/CutTools.
The compilation fails with the following output message:
    cp -p ./src/cts/cts_qpr.in ./src/cts/cts_mpr.h
    mkdir -p includects
    cp -p ./src/avh/* includects/
    cp -p ./src/cts/cts_qpc.in ./src/cts/cts_mpc.h
    cp -p ./src/cts/cts_qprec.in ./src/cts/cts_mprec.h
    cp -p ./src/cts/cts_qpinit.in ./src/cts/cts_mpinit.h
    cp -p ./src/cts/* includects/
    cp -p ./src/mpfun90/* includects/
    cp -p ./src/qcdloop/* includects/
    cp -p ./src/makefile includects/
    cd includects && make EXE="" FC="gfortran" FFLAGS="-fPIC -fno-automatic -O2 -funroll-all-loops" default
    make[1]: Entering directory `/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/vendor/CutTools/includects'
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c mpfun90.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c mpmod90.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c mpmodm90.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c mpmodx90.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c avh_olo.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_type.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_tensors.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_constants.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_combinatorics.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_dynamics.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_kinematics.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_loopfunctions.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_cuttools.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -c cts_cutroutines.f90
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aaxbx.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aaxcx.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aaxdx.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aaxex.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aaxinv.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aacbc.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aaccc.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c aacinv.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c spence.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c npoin.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ff2dl2.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffabcd.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffca0.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcb0.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcb1.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcb2.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcb2p.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcdb0.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcc0.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcc0p.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcc1.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcel2.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcel3.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcel4.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcel5.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffceta.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcli2.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcrr.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcxr.f
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcxs3.f
    mpmod90.f90:43:5:

       43 | use mpfunmod
          | 1
    Fatal Error: Cannot open module file 'mpfunmod.mod' for reading at (1): No such file or directory
    compilation terminated.
    gfortran -fPIC -fno-automatic -O2 -funroll-all-loops -std=legacy -c ffcxs4.f
    make[1]: *** [mpmod90.o] Error 1
    make[1]: *** Waiting for unfinished jobs....
    mpmodm90.f90:34:5:

       34 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [mpmodm90.o] Error 1
    mpmodx90.f90:32:5:

       32 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [mpmodx90.o] Error 1
    make[1]: *** [cts_tensors.o] Error 1
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [cts_type.o] Error 1
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    make[1]: *** [cts_dynamics.o] Error 1
    compilation terminated.
    make[1]: *** [cts_constants.o] Error 1
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [cts_cuttools.o] Error 1
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [cts_cutroutines.o] Error 1
    aaxex.f:464:35:

      463 | do i=16,35
          | 2
      464 | cexi(i) = ce3ijk(m2ijk(1,i),m2ijk(2,i),m2ijk(3,i))
          | 1
    Warning: Array reference at (1) out of bounds (35 > 20) in loop beginning at (2)
    aaxex.f:464:46:

      463 | do i=16,35
          | 2
      464 | cexi(i) = ce3ijk(m2ijk(1,i),m2ijk(2,i),m2ijk(3,i))
          | 1
    Warning: Array reference at (1) out of bounds (35 > 20) in loop beginning at (2)
    aaxex.f:464:57:

      463 | do i=16,35
          | 2
      464 | cexi(i) = ce3ijk(m2ijk(1,i),m2ijk(2,i),m2ijk(3,i))
          | 1
    Warning: Array reference at (1) out of bounds (35 > 20) in loop beginning at (2)
    cts_loopfunctions.f90:7:7:

        7 | use denominators
          | 1
    Fatal Error: Cannot open module file 'denominators.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [cts_loopfunctions.o] Error 1
    aaxex.f:464:72:

      464 | cexi(i) = ce3ijk(m2ijk(1,i),m2ijk(2,i),m2ijk(3,i))
          | ^
    Warning: iteration 4 invokes undefined behavior [-Waggressive-loop-optimizations]
    aaxex.f:463:11:

      463 | do i=16,35
          | ^
    note: within this loop
    cts_mprec.h:1:7:

        1 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [cts_kinematics.o] Error 1
    avh_olo.f90:23477:7:

    23477 | use mpmodule
          | 1
    Fatal Error: Cannot open module file 'mpmodule.mod' for reading at (1): No such file or directory
    compilation terminated.
    make[1]: *** [avh_olo.o] Error 1
    make[1]: Leaving directory `/lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/vendor/CutTools/includects'
    make: *** [default] Error 2

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
                          MadGraph5_aMC@NLO Options
                          ----------------
                auto_update : 7
        complex_mass_scheme : False
    default_unset_couplings : 99
                      gauge : unitary
         group_subprocesses : Auto
  ignore_six_quark_processes : False
  include_lepton_initiated_processes : False
           loop_color_flows : False
      loop_optimized_output : True
  low_mem_multicore_nlo_generation : False
     max_npoint_for_channel : 0
          max_t_for_channel : 99
        nlo_mixed_expansion : True
               stdout_level : 20 (user set)
         zerowidth_tchannel : True

                         MadEvent Options
                          ----------------
     automatic_html_opening : True
                    nb_core : 4 (user set)
        notification_center : True
                   run_mode : 2

                      Configuration Options
                      ---------------------
                        OLP : MadLoop
   acknowledged_v3.1_syntax : False
         auto_convert_model : False
         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 : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/lib (user set)
                contur_path : ./HEPTools/contur
               cpp_compiler : None
             crash_on_error : False
               delphes_path : ./Delphes
                 eps_viewer : None
        exrootanalysis_path : ./ExRootAnalysis
              f2py_compiler : None
          f2py_compiler_py2 : None
          f2py_compiler_py3 : None
                    fastjet : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/bin/fastjet-config (user set)
           fortran_compiler : None
                      golem : None (user set)
                 hepmc_path : None (user set)
                  hwpp_path : None (user set)
                     lhapdf : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/lhapdf6_py3/bin/lhapdf-config (user set)
                 lhapdf_py2 : None
                 lhapdf_py3 : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/lhapdf6_py3/bin/lhapdf-config (user set)
          madanalysis5_path : None (user set)
           madanalysis_path : ./MadAnalysis
  mg5amc_py8_interface_path : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/MG5aMC_PY8_interface (user set)
                      ninja : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/lib (user set)
        output_dependencies : external
                   pineappl : pineappl
            pythia-pgs_path : ./pythia-pgs
               pythia8_path : /lustre/ific.uv.es/grid/atlas/t3/asaibel/TTbarGamma/MG5_aMC_v3_4_2/HEPTools/pythia8 (user set)
                 rivet_path : ./HEPTools/rivet
                    samurai : None
               syscalc_path : ./SysCalc
                    td_path : ./td
                text_editor : emacs (user set)
                thepeg_path : None (user set)
                    timeout : 60
                web_browser : None
yoda_path : ./HEPTools/yoda