Is upstream-bug?

When filing a bug-report, make sure it is indeed a bug in this plugin, and not an upstream (lldb) bug. To that end, please execute the following script in your Python2 REPL, and provide its output:

import lldb

dbg = lldb.SBDebugger.Create()
ci = dbg.GetCommandInterpreter()

def execute(command):
    res = lldb.SBCommandReturnObject()
    ci.HandleCommand(command, res)
    print(res.Succeeded(), res.GetOutput(), res.GetError())

# now execute each command as follows:
execute("target create ...")
execute("your command here")

...output here...