Repro.cs

using Roslyn.Scripting.CSharp;
using System;
namespace RoslynTests
{
    class Program
    {
        static void Main(string[] args)
        {
            var script = "using System; public class Test{ public void Do<T>() where T : IDisposable{ } }";

            ScriptEngine engine = new ScriptEngine();

            var session = engine.CreateSession();
            
            // throws
            var submission = session.CompileSubmission<object>(script);
            
            var execution = submission.Execute();
        }
    }
}