How do I prevent gemspec from pushing anywhere?

Usually, when I develop it on ruby, I develop it by cutting out what can be made into OSS to the public gem, and the common processing across personal projects to the private gem.

With this development, rake release is ready to be released at least if you are developing a public gem.

On the other hand, I have no plans to run rake release for private gem, but I would like to prevent it from being released to rubygems.org and published worldwide if I accidentally run it.

• Is it possible to write a gemspec that cannot be released anywhere when developing a private gem?