如何使用pip安装特定版本的软件包?

可能重复:
使用Pip安装特定的软件包版本

Possible Duplicate:
Installing specific package versions with Pip

我对pip install和virtualenv有点陌生.

我已经在服务器以及本地开发环境上设置了virtualenv.

I have setup an virtualenv on my server as well as on my local dev environment.

在服务器上，软件包django_modeltranslation-0.4.0_beta2可以正常工作.

On the server the package django_modeltranslation-0.4.0_beta2 works perfectly fine.

但是在我的本地计算机上django_modeltranslation-0.5.0-alpha似乎根本无法正常工作.

However on my local machine django_modeltranslation-0.5.0-alpha doesn't seem to work well at all.

我通常像这样简单地将其安装在virtual-env中:

I usually simply install it in virtual-env like this:

$ source bin/active
(env)$ pip install django_modeltranslation

尽管它获得了最新版本，但现在第一次导致使用最新版本的问题.

This gets the latest version though, which now for the first time causes issues working with latest version.

所以我已经像这样卸载了版本5 alpha:

So I have uninstalled the version 5 alpha like this:

(env)$ pip uninstall django_modeltranslation

但是现在我不知道如何才能再次获得工作版本0.4.0 Beta. 我尝试过，但是找不到:

But now I don't know how I could get the working version 0.4.0 Beta again. I tried this but it couldn't find it:

(env)$ pip install django_modeltranslation-0.4.0_beta2
Downloading/unpacking django-modeltranslation-0.4.0-beta2
  Could not find any downloads that satisfy the requirement django-modeltranslation-0.4.0-beta2
No distributions at all found for django-modeltranslation-0.4.0-beta2

我认为必须有一种方法，因为这是使用虚拟环境的全部要点.

I think there must be a way, since that is the whole point of using virtual env.