In _import_optional, you will see
s.do_mkdir('.shellista_tmp')
This needs to point to someplace writable.
I suspect the default editorial path is under Library, and is not writable.
What does os.path.expanduser('~') return?
Try inserting os.chdir('../../../Documents') before the do_mkdir.(or whatever it takes to get to Documents.. Might need to play around with os.chdir and os.curdir, and os.listdir.)
Also, inside Shell init:
self._bash.env_vars['$HOME'] = os.path.expanduser('~/Documents')
Your should this to point to the Editorial Documents folder, which I'm guessing might be
self._bash.env_vars['$HOME'] = os.path.expanduser('~/../../../Documents')
If you get it working, be sure to post back, or post a pull request or issue into the repo. we can try to add some kind of detection into shellista to detect editorial vs pythonista,etc.