TypeError: __init__() got an unexpected keyword argument 'metavar'

[caot]

Just installed the most recent update, however it got the mentioned error. What might be the issue?

$ MAGIC.py
Traceback (most recent call last):
  File "/opt/anaconda3/bin/MAGIC.py", line 120, in <module>
    main(sys.argv[1:])
  File "/opt/anaconda3/bin/MAGIC.py", line 82, in main
    args = parse_args(args)
  File "/opt/anaconda3/bin/MAGIC.py", line 69, in parse_args
    help='Plot R2 plot generated in optimal t calculation (Default=False).')
  File "/opt/anaconda3/lib/python3.6/argparse.py", line 1334, in add_argument
    action = action_class(**kwargs)
TypeError: __init__() got an unexpected keyword argument 'metavar'

$ git log -n 1
commit 044038e4b70a79af4950a63075c3aaeb51eea893
Merge: 0929f2b 03bb376
Author: Pooja Kathail <pk2485@columbia.edu>
Date:   Fri Jan 26 17:19:52 2018 -0500

    fix merge conflicts

[caot]

removed unexpected keyword argument 'metavar'