subprocess.CalledProcessError: Command '['isolate', '--cg', '--box-id=12', '--cleanup']' returned non-zero exit status 2

Question

While trying to setup following CMS: https://github.com/cms-dev/cms/tree/v1.4, I used cmsWorker inside Terminal to start the Worker process.

After Worker received a submission, it threw following error:

Traceback (most recent call last):
  File "/home/sl/cms_venv/lib/python3.8/site-packages/cms-1.5.dev0-py3.8.egg/cms/service/Worker.py", line 131, in execute_job_group
    task_type.execute_job(job, self.file_cacher)
  File "/home/sl/cms_venv/lib/python3.8/site-packages/cms-1.5.dev0-py3.8.egg/cms/grading/tasktypes/abc.py", line 226, in execute_job
    self.compile(job, file_cacher)
  File "/home/sl/cms_venv/lib/python3.8/site-packages/cms-1.5.dev0-py3.8.egg/cms/grading/tasktypes/Batch.py", line 227, in compile
    sandbox = create_sandbox(file_cacher, name="compile")
  File "/home/sl/cms_venv/lib/python3.8/site-packages/cms-1.5.dev0-py3.8.egg/cms/grading/tasktypes/util.py", line 62, in create_sandbox
    sandbox = Sandbox(file_cacher, name=name)
  File "/home/sl/cms_venv/lib/python3.8/site-packages/cms-1.5.dev0-py3.8.egg/cms/grading/Sandbox.py", line 940, in __init__
    self.cleanup()
  File "/home/sl/cms_venv/lib/python3.8/site-packages/cms-1.5.dev0-py3.8.egg/cms/grading/Sandbox.py", line 1444, in cleanup
    subprocess.check_call(
  File "/home/sl/cms_venv/lib/python3.8/site-packages/gevent/subprocess.py", line 316, in check_call
    raise CalledProcessError(retcode, cmd) # pylint:disable=undefined-variable
subprocess.CalledProcessError: Command '['isolate', '--cg', '--box-id=12', '--cleanup']' returned non-zero exit status 2.

The error itself seems to be related to the isolate, which could be related to this: https://github.com/ioi/isolate.

Useful piece of information can be found here: http://www.ucw.cz/moe/isolate.1.html