This post originated from an RSS feed registered with .NET Buzz by Jeff Key. Original Post: Determining if a C#/VB.NET assembly was compiled as DEBUG or RELEASE Feed Title: Jeff Key Feed URL: http://www.asp.net/err404.htm?aspxerrorpath=/jkey/Rss.aspx Feed Description: Topics revolve around .NET and the Windows platform. Latest .NET Buzz Posts Latest .NET Buzz Posts by Jeff Key Latest Posts From Jeff Key

I had to figure this out a couple days ago and the answer isn't what you'd expect:  It's not FileVersionInfo.IsDebug or IsRelease, as neither compiler flips the required bit.  As far as I can tell, the only way is to look for a DebuggableAttribute on the assembly.

static void Main(string[] args) 
{
    Assembly assm = Assembly.LoadFrom(args[0]);
    bool found = assm.GetCustomAttributes(typeof(DebuggableAttribute), false).Length > 0;
    Console.WriteLine("Assembly is {0}.", found ? "debug" : "release");
}