# Buggy code
def from_parts(cls, project, profile, args):
    """Instantiate a RuntimeConfig from its components.

    :param profile Profile: A parsed dbt Profile.
    :param project Project: A parsed dbt Project.
    :param args argparse.Namespace: The parsed command-line arguments.
    :returns RuntimeConfig: The new configuration.
    """
    quoting = deepcopy(
        get_relation_class_by_name(profile.credentials.type).DEFAULTS["quote_policy"]
    )
    quoting.update(project.quoting)
    return cls(
        project_name=project.project_name,
        version=project.version,
        project_root=project.project_root,
        source_paths=project.source_paths,
        macro_paths=project.macro_paths,
        data_paths=project.data_paths,
        test_paths=project.test_paths,
        analysis_paths=project.analysis_paths,
        docs_paths=project.docs_paths,
        target_path=project.target_path,
        clean_targets=project.clean_targets,
        log_path=project.log_path,
        modules_path=project.modules_path,
        quoting=quoting,
        models=project.models,
        on_run_start=project.on_run_start,
        on_run_end=project.on_run_end,
        archive=project.archive,
        seeds=project.seeds,
        packages=project.packages,
        profile_name=profile.profile_name,
        target_name=profile.target_name,
        send_anonymous_usage_stats=profile.send_anonymous_usage_stats,
        use_colors=profile.use_colors,
        threads=profile.threads,
        credentials=profile.credentials,
        args=args,
    )


# Traceback (PermissionError)
[Errno 13] Permission denied: '/.dbt'
Traceback (most recent call last):
File "/usr/local/lib/python3.7/site-packages/dbt/main.py", line 76, in main
results, succeeded = handle_and_check(args)
File "/usr/local/lib/python3.7/site-packages/dbt/main.py", line 120, in handle_and_check
dbt.tracking.initialize_tracking()
File "/usr/local/lib/python3.7/site-packages/dbt/tracking.py", line 275, in initialize_tracking
active_user.initialize()
File "/usr/local/lib/python3.7/site-packages/dbt/tracking.py", line 51, in initialize
cookie = self.get_cookie()
File "/usr/local/lib/python3.7/site-packages/dbt/tracking.py", line 71, in get_cookie
user = self.set_cookie()
File "/usr/local/lib/python3.7/site-packages/dbt/tracking.py", line 62, in set_cookie
dbt.clients.system.make_directory(cookie_dir)
File "/usr/local/lib/python3.7/site-packages/dbt/clients/system.py", line 85, in make_directory
raise e
File "/usr/local/lib/python3.7/site-packages/dbt/clients/system.py", line 79, in make_directory
os.makedirs(path)
File "/usr/local/lib/python3.7/os.py", line 221, in makedirs
mkdir(name, mode)
PermissionError: [Errno 13] Permission denied: '/.dbt'

# Fixed code
def from_parts(cls, project, profile, args):
    """Instantiate a RuntimeConfig from its components.

    :param profile Profile: A parsed dbt Profile.
    :param project Project: A parsed dbt Project.
    :param args argparse.Namespace: The parsed command-line arguments.
    :returns RuntimeConfig: The new configuration.
    """
    quoting = deepcopy(
        get_relation_class_by_name(profile.credentials.type).DEFAULTS["quote_policy"]
    )
    quoting.update(project.quoting)
    return cls(
        project_name=project.project_name,
        version=project.version,
        project_root=project.project_root,
        source_paths=project.source_paths,
        macro_paths=project.macro_paths,
        data_paths=project.data_paths,
        test_paths=project.test_paths,
        analysis_paths=project.analysis_paths,
        docs_paths=project.docs_paths,
        target_path=project.target_path,
        clean_targets=project.clean_targets,
        log_path=project.log_path,
        modules_path=project.modules_path,
        quoting=quoting,
        models=project.models,
        on_run_start=project.on_run_start,
        on_run_end=project.on_run_end,
        archive=project.archive,
        seeds=project.seeds,
        packages=project.packages,
        profile_name=profile.profile_name,
        target_name=profile.target_name,
        config=profile.config,
        threads=profile.threads,
        credentials=profile.credentials,
        args=args,
    )