Traceback (most recent call last):
  File "/usr/bin/add-apt-repository", line 119, in <module>
    shortcut = shortcut_handler(line)
  File "/usr/lib/python3/dist-packages/softwareproperties/SoftwareProperties.py", line 837, in shortcut_handler
    ret = factory(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 382, in shortcut_handler
    return PPAShortcutHandler(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 345, in __init__
    self.shortcut = mangle_ppa_shortcut(shortcut)
  File "/usr/lib/python3/dist-packages/softwareproperties/ppa.py", line 133, in mangle_ppa_shortcut
    if (user[0] == "~"):
IndexError: string index out of range