How do I set specific environment variables when debugging in Visual Studio?

In Visual Studio 2008 and Visual Studio 2005 at least, you can specify changes to environment variables in the project settings.

Open your project. Go to Project -> Properties... Under Configuration Properties -> Debugging, edit the 'Environment' value to set environment variables.

For example, if you want to add the directory "c:\foo\bin" to the path when debugging your application, set the 'Environment' value to "PATH=%PATH%;c:\foo\bin".

In Visual Studio for Mac and C# you can use:

Environment.SetEnvironmentVariable("<Variable_name>", "<Value>");

But you will need the following namespace

using System.Collections;

you can check the full list of variables with this:

foreach (DictionaryEntry de in Environment.GetEnvironmentVariables())
            Console.WriteLine("  {0} = {1}", de.Key, de.Value);