Merge pull request #751 from JakeGinnivan/NicerErrorWhenGitMissingOnDumpGraph

Display nicer error message when git is not on the path and GitVersio…

Author: JakeGinnivan

src/GitVersionCore/Helpers/ProcessHelper.cs

@@ -48,7 +48,7 @@ public static Process Start(ProcessStartInfo startInfo)
         // http://csharptest.net/532/using-processstart-to-capture-console-output/
         public static int Run(Action<string> output, Action<string> errorOutput, TextReader input, string exe, string args, string workingDirectory, params KeyValuePair<string, string>[] environmentalVariables)
         {
-            if (String.IsNullOrEmpty(exe))
+            if (string.IsNullOrEmpty(exe))
                 throw new ArgumentNullException("exe");
 
             if (output == null)

src/GitVersionCore/LibGitExtensions.cs

@@ -267,12 +267,9 @@ public static void DumpGraph(string workingDirectory, Action<string> writer = nu
             catch (FileNotFoundException exception)
             {
                 if (exception.FileName != "git")
-                {
                     throw;
-                }
 
-                output.AppendLine("Could not execute 'git log' due to the following error:");
-                output.AppendLine(exception.ToString());
+                output.AppendLine("Unable to display git log (due to 'git' not being on the %PATH%), this is just for debugging purposes to give more information to track down your issue. Run gitversion debug locally instead.");
             }
 
             if (writer != null) writer(output.ToString());