Crash when running madevent

Hi all,

Hopefully it is fine that I turn this unanswered question into a bug report, as it appears to be a genuine bug in v3.4.2 that I also see.
Quoted question below:

Hi,

I am running Madgraph 3.4.2 on Ubuntu 22.04 and it is working well.

Here I take p p > e e as an example, it works if I generate p p > e e and launch inside Madgraph. However, if I want to run the madevent inside the process folder, it gives me some Python error, see below

$ ./ppee/bin/madevent
launch in debug mode
************************************************************
* *
* W E L C O M E to *
* M A D G R A P H 5 _ a M C @ N L O *
* M A D E V E N T *
* *
* * * *
* * * * * *
* * * * * 5 * * * * *
* * * * * *
* * * *
* *
* VERSION 3.4.2 2023-01-20 *
* *
* The MadGraph5_aMC@NLO Development Team - Find us at *
* https://server06.fynu.ucl.ac.be/projects/madgraph *
* *
* Type 'help' for in-line help. *
* *
************************************************************
Traceback (most recent call last):
  File "/home/yang/work/MG5_aMC_v3_4_2/bin/./ppee/bin/madevent", line 200, in <module>
    cmd_line = cmd_interface.MadEventCmdShell(force_run=True)
  File "/home/yang/work/MG5_aMC_v3_4_2/bin/ppee/bin/internal/madevent_interface.py", line 2091, in __init__
    CmdExtended.__init__(self, me_dir, options, *completekey, **stdin)
  File "/home/yang/work/MG5_aMC_v3_4_2/bin/ppee/bin/internal/madevent_interface.py", line 206, in __init__
    super(CmdExtended, self).__init__(me_dir, options, *arg, **opt)
  File "/home/yang/work/MG5_aMC/madgraph/interface/common_run_interface.py", line 690, in __init__
    if os.path.isabs(me_dir):
  File "/usr/lib/python3.10/posixpath.py", line 62, in isabs
    s = os.fspath(s)
TypeError: expected str, bytes or os.PathLike object, not NoneType