Explicitly throw a FileNotFoundException if the exe file does not exist instead of relying on Process.Start() to do it, since it doesn't say anything about which file it can't find (which makes debugging very hard).

Author: asbjornu

GitVersionCore/Helpers/ProcessHelper.cs

@@ -36,6 +36,12 @@ public static int Run(Action<string> output, Action<string> errorOutput, TextRea
             if (output == null)
                 throw new ArgumentNullException("output");
 
+            workingDirectory = workingDirectory ?? Environment.CurrentDirectory;
+            var exePath = Path.Combine(workingDirectory, exe);
+
+            if (!File.Exists(exePath))
+                throw new FileNotFoundException(String.Format("The executable file '{0}' does not exist.", exePath), exePath);
+
             var psi = new ProcessStartInfo
             {
                 UseShellExecute = false,
@@ -45,7 +51,7 @@ public static int Run(Action<string> output, Action<string> errorOutput, TextRea
                 WindowStyle = ProcessWindowStyle.Hidden,
                 CreateNoWindow = true,
                 ErrorDialog = false,
-                WorkingDirectory = workingDirectory ?? Environment.CurrentDirectory,
+                WorkingDirectory = workingDirectory,
                 FileName = exe,
                 Arguments = args
             };