# Buggy code
def process_service(service_config):
    working_dir = service_config.working_dir
    service_dict = dict(service_config.config)

    if "env_file" in service_dict:
        service_dict["env_file"] = [
            expand_path(working_dir, path) for path in to_list(service_dict["env_file"])
        ]

    if "build" in service_dict:
        if isinstance(service_dict["build"], six.string_types):
            service_dict["build"] = resolve_build_path(
                working_dir, service_dict["build"]
            )
        elif isinstance(service_dict["build"], dict):
            if "context" in service_dict["build"]:
                path = service_dict["build"]["context"]
                service_dict["build"]["context"] = resolve_build_path(working_dir, path)
            if "labels" in service_dict["build"]:
                service_dict["build"]["labels"] = parse_labels(
                    service_dict["build"]["labels"]
                )

    if "volumes" in service_dict and service_dict.get("volume_driver") is None:
        service_dict["volumes"] = resolve_volume_paths(working_dir, service_dict)

    if "sysctls" in service_dict:
        service_dict["sysctls"] = build_string_dict(
            parse_sysctls(service_dict["sysctls"])
        )

    service_dict = process_depends_on(service_dict)

    for field in ["dns", "dns_search", "tmpfs"]:
        if field in service_dict:
            service_dict[field] = to_list(service_dict[field])

    service_dict = process_blkio_config(
        process_ports(process_healthcheck(service_dict))
    )

    return service_dict


# Traceback (ValueError)
Traceback (most recent call last):
File "/bin/docker-compose", line 11, in <module>
sys.exit(main())
File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 68, in main
command()
File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 121, in perform_command
handler(command, command_options)
File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 768, in run
run_one_off_container(container_options, self.project, service, options)
File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 1178, in run_one_off_container
**container_options)
File "/usr/lib/python2.7/site-packages/compose/service.py", line 288, in create_container
previous_container=previous_container,
File "/usr/lib/python2.7/site-packages/compose/service.py", line 795, in _get_container_create_options
self.config_hash if add_config_hash else None)
File "/usr/lib/python2.7/site-packages/compose/service.py", line 1338, in build_container_labels
labels = dict(label_options or {})
ValueError: dictionary update sequence element #0 has length 35; 2 is required

# Fixed code
def process_service(service_config):
    working_dir = service_config.working_dir
    service_dict = dict(service_config.config)

    if "env_file" in service_dict:
        service_dict["env_file"] = [
            expand_path(working_dir, path) for path in to_list(service_dict["env_file"])
        ]

    if "build" in service_dict:
        process_build_section(service_dict, working_dir)

    if "volumes" in service_dict and service_dict.get("volume_driver") is None:
        service_dict["volumes"] = resolve_volume_paths(working_dir, service_dict)

    if "sysctls" in service_dict:
        service_dict["sysctls"] = build_string_dict(
            parse_sysctls(service_dict["sysctls"])
        )

    if "labels" in service_dict:
        service_dict["labels"] = parse_labels(service_dict["labels"])

    service_dict = process_depends_on(service_dict)

    for field in ["dns", "dns_search", "tmpfs"]:
        if field in service_dict:
            service_dict[field] = to_list(service_dict[field])

    service_dict = process_blkio_config(
        process_ports(process_healthcheck(service_dict))
    )

    return service_dict