我正在尝试设置 RabbitMQ，但我的依赖项出现了一些问题。我正在运行 Debian 7.1，它将用作服务器，因此没有桌面环境。我尝试使用 aptitude 安装 rabbitmq-server：
$ apt-get install rabbitmq-server
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package rabbitmq-server is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source.
E: Package 'rabbitmq-server' has no installation candidate
从 RabbitMQ 站点获取 .deb 文件会产生以下依赖性错误：
$ dpkg -i rabbitmq-server_3.1.3-1_all.deb
Selecting previously unselected package rabbitmq-server.
(Reading database ... 31422 files and directories currently installed.)
Unpacking rabbitmq-server (from rabbitmq-server_3.1.3-1_all.deb) ...
dpkg: dependency problems prvent configuration of rabbitmq-server:
rabbitmq-server depends on erlang-nox (>= 1:12.b.3) | esl-erlang; however:
Package erlang-nox is not installed.
Package esl-erlang is not installed.
尝试单独安装 erlang-nox 会产生类似的结果：
$ apt-get install erlang-nox
Reading package lists... Done
Building dependency tree
Reading state information... Done
Package erlang-nox is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or is only available from another source.
E: Package 'erlang-nox' has no installation candidate
我的信息来源列表如下：
$ cat /etc/apt/sources.list
...
deb http://security.debian.org wheezy/updates main contrib
deb-src http://security.debian.org wheezy/updates main contrib
#deb http://www.rabbitmq.com/debian testing main
最后一行是在我通过上述步骤安装 rabbiqmq-server 失败后添加的，但也不起作用。
我尝试手动安装 erlang（编译并使用 make install），但 rabbitmq 仍然抱怨它并且无法安装。
有什么迹象表明这里可能出了什么问题？