$ /snap/bin/snapcraft --help
Traceback (most recent call last):
  File "/snap/snapcraft/2496/bin/snapcraft", line 11, in <module>
    load_entry_point('snapcraft==3.1', 'console_scripts', 'snapcraft')()
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/snapcraft/cli/__main__.py", line 81, in run
    run_snapcraft(prog_name="snapcraft")
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 722, in __call__
    return self.main(*args, **kwargs)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 696, in main
    with self.make_context(prog_name, args, **extra) as ctx:
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 621, in make_context
    self.parse_args(ctx, args)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 1018, in parse_args
    rest = Command.parse_args(self, ctx, args)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 880, in parse_args
    value, args = param.handle_parse_result(ctx, opts, args)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 1404, in handle_parse_result
    self.callback, ctx, self, value)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 78, in invoke_param_callback
    return callback(ctx, param, value)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 809, in show_help
    echo(ctx.get_help(), color=ctx.color)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 496, in get_help
    return self.command.get_help(self)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 830, in get_help
    self.format_help(ctx, formatter)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 845, in format_help
    self.format_options(ctx, formatter)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 956, in format_options
    self.format_commands(ctx, formatter)
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/click/core.py", line 1000, in format_commands
    for subcommand in self.list_commands(ctx):
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/snapcraft/cli/_command_group.py", line 69, in list_commands
    build_environment = env.BuilderEnvironmentConfig()
  File "/snap/snapcraft/2496/lib/python3.5/site-packages/snapcraft/cli/env.py", line 57, in __init__
    humanize_list(items=valid_providers, conjunction="or")
snapcraft.internal.errors.SnapcraftEnvironmentError: The snapcraft build environment must be one of: 'host', 'managed-host', or 'multipass'.