Ensure Flax.Build tasks and utilities output error messages as errors

Source/Tools/Flax.Build/Build/Graph/LocalExecutor.cs

@@ -237,7 +237,7 @@ namespace Flax.Build.BuildSystem.Graph
                         CreateNoWindow = true,
                     };
                     process.OutputDataReceived += ProcessDebugOutput;
-                    process.ErrorDataReceived += ProcessDebugOutput;
+                    process.ErrorDataReceived += ProcessDebugError;
                     process.Start();
 
                     process.BeginOutputReadLine();
@@ -273,5 +273,14 @@ namespace Flax.Build.BuildSystem.Graph
                 Log.Info(output);
             }
         }
+
+        private static void ProcessDebugError(object sender, DataReceivedEventArgs e)
+        {
+            string output = e.Data;
+            if (output != null)
+            {
+                Log.Error(output);
+            }
+        }
     }
 }

Source/Tools/Flax.Build/Utilities/Utilities.cs

@@ -423,6 +423,14 @@ namespace Flax.Build
             }
         }
 
+        private static void StdLogError(object sender, DataReceivedEventArgs e)
+        {
+            if (e.Data != null)
+            {
+                Log.Error(e.Data);
+            }
+        }
+
         private static void StdLogVerbose(object sender, DataReceivedEventArgs e)
         {
             if (e.Data != null)
@@ -513,7 +521,7 @@ namespace Flax.Build
                 if (options.HasFlag(RunOptions.ConsoleLogOutput))
                 {
                     proc.OutputDataReceived += StdLogInfo;
-                    proc.ErrorDataReceived += StdLogInfo;
+                    proc.ErrorDataReceived += StdLogError;
                 }
                 else
                 {