如何在使用run（）函数的fab部署下处理django迁移

Question

我有以下用于迁移开发的fabfile.py Django代码生产。

#--------------------------------------------------
# This script enable separation of development and production.
#--------------------------------------------------
from fabric.api import run, local, env, put, sudo
from fabric.contrib.project import rsync_project

env.hosts = ["bosswebserver"]
env.static_path = "/u33/app/www/coolapp/html/coolapp/"
env.app_path = "/u33/app/www/coolapp/wsgi-scripts/coolapp/"





def collect_static():
    local('python manage.py collectstatic --noinput --settings=webframework.settings.dev')

def deploy_static():
    rsync_project(local_dir='.static/.',
                  remote_dir=env.static_path,
                  delete=True,
                  extra_opts='--no-perms --no-times')

def deploy_app():
    rsync_project(local_dir='.',
                  remote_dir=env.app_path,
                  delete=True,
                  exclude=['.static', 'user_files'],
                  extra_opts='--no-perms --no-times')

def migrate_db():
    run('python {app_path}manage.py migrate --settings=webframework.settings.prod'.format(**env))

def restart_server():
    run('sudo /usr/local/bin/httpd_restart')

def deploy():
    collect_static()

    deploy_static()
    deploy_app()
    migrate_db()  # break here

    restart_server()

现在我做的时候

$ fab deploy

我最后收到了这条消息：

webframework/settings/dev.py
webframework/settings/prod.py

sent 15.59K bytes  received 160.09K bytes  117.12K bytes/sec
total size is 25.46M  speedup is 144.92
[ bosswebserver] run: python /u33/app/www/coolapp/wsgi-scripts/coolapp/manage.py migrate --settings=webframework.settings.prod

Fatal error: run() received nonzero return code -1 while executing!

Requested: python /u33/app/www/coolapp/wsgi-scripts/coolapp/manage.py migrate --settings=webframework.settings.prod
Executed: /bin/bash -l -c "python /u33/app/www/coolapp/wsgi-scripts/coolapp/manage.py migrate --settings=webframework.settings.prod"

Aborting.
Disconnecting from bosswebserver... done.

我该如何解决这个问题？

更新：

我试过这个，通过在前面添加r来实现它：

def migrate_db():
    run(r'python /u33/app/www/coolapp/wsgi-scripts/coolapp/manage.py migrate --settings=webframework.settings.prod')

然而，我仍然为何失败感到困惑：

def migrate_db():
    run('python {app_path}manage.py migrate --settings=webframework.settings.prod'.format(**env))