"fatal: external diff died, stopping at ...", subprocess.CalledProcessError: Command '['git', 'show', '--pretty=format:', '--ext-diff', 'HEAD']' returned non-zero exit status 128.

[motemen]

% furo2 history show HEAD
[less starts and hit q to quit immediately before the end]
fatal: external diff died, stopping at 2018/06/20/190506.859525.log
Traceback (most recent call last):
  File "/usr/local/bin/furo2", line 11, in <module>
    load_entry_point('furo2==2.0.0a0', 'console_scripts', 'furo2')()
  File "/usr/local/Cellar/furoshiki2/HEAD-8ba9625/libexec/lib/python3.6/site-packages/furo2/furo2.py", line 233, in run
    command_history(args)
  File "/usr/local/Cellar/furoshiki2/HEAD-8ba9625/libexec/lib/python3.6/site-packages/furo2/furo2.py", line 174, in command_history
    git(['show', '--pretty=format:', '--ext-diff'] + args)
  File "/usr/local/Cellar/furoshiki2/HEAD-8ba9625/libexec/lib/python3.6/site-packages/furo2/furo2.py", line 50, in git
    subprocess.check_call(['git'] + args, **kwargs)
  File "/usr/local/opt/python3/Frameworks/Python.framework/Versions/3.6/lib/python3.6/subprocess.py", line 291, in check_call
    raise CalledProcessError(retcode, cmd)
subprocess.CalledProcessError: Command '['git', 'show', '--pretty=format:', '--ext-diff', 'HEAD']' returned non-zero exit status 128.