Heroku restart = Resource not found?

I'm using Heroku to deploy a Rails3 App for months.

Until now, deploying my app was really straightforward.. (I'm using heroku san to manage environments like staging or production) .. but today, the command "restart" give me a nice "Resource not found" error.

I can't understan开发者_StackOverflowd why because the others commands works (console, rake db:migrate, ...)

Good :

heroku console --app my_app  
heroku rake db:migrate --app my_app  
heroku stack --app my_app  
etc...

Not good :

heroku restart --app my_app

Any suggestions ? Thx.

Here's the full Terminal command and result :

me@computer:my_app_folder(master)$ heroku restart --app my_app
Resource not found

There's nothing else...

The solution was obvious...

gem update heroku

The update fix this issue. Here's my gems versions :

heroku (2.4.2, 1.17.10)
heroku_san (1.2.3, 1.2.0)