ASP.NET Core Environment Variables With Semicolon in Jenkins

In my ASP.NET Core project, I am using an environment variable in the form of MyProject:MyVariableName and needed to create a Jenkins pipeline but I could not get it to recognize that format. It kept making the environment variable name just MyVariableName.

Below is the code from the Jenkinsfile that I tried that was causing the issue.

stage('Run All Test') {
    environment {
        MyProject:MyVariableName = "Some Value"
    }
}

Turns out that Jenkins does not recognize the : in environment variable names. After much searching, I ran across this article that mentioned that not all platforms support : in the environment names and that for those environmments you can use a double underscore __

So I updated the Jenkinsfile code above with the double underscore __ and this make Jenkins see the environment variable name as MyProject:MyVariableName

stage('Run All Test') {
    environment {
        MyProject__MyVariableName = "Some Value"
    }
}