gh pull-request won't start with flags in core.editor

For example,

    [core]
      editor = vim --noplugin

This gives me:
    2013/11/26 13:32:04 fatal: command not found: /usr/bin/vim --noplugin

While this works fine

    [core]
      editor = vim

Meanwhile, [hub](hub.github.com) works with both cases.