How to let tramp be aware the virtualenv?

[Zhongwei Yao]

Hi, all,
I try to use tramp on a remote project directory and run "M-x compile". The
command requires to know which the python virtualenv is active.

I try to let tramp be ware of which virtualenv is active by adding a line
to the remote $HOME/.profile like (because it seems tramp will run the
compilation command by the remote /bin/sh):

  source my/python/virtualenv/bin/activate.

But tramp seems doesn't read that line at all. The virtualenv is not
activated.

So how can I make tramp aware of which virtualenv is enabled?

Thanks!
Zhongwei