Ensures that the work directory exists.
    In addition, the location of the workdir is stored as attribute in
    the context object.

def ensure_workdir_exists(context):
    """
    Ensures that the work directory exists.
    In addition, the location of the workdir is stored as attribute in
    the context object.
    """
    ensure_context_attribute_exists(context, "workdir", None)
    if not context.workdir:
        context.workdir = os.path.abspath(WORKDIR)
    pathutil.ensure_directory_exists(context.workdir)