dotnet run --no-build

test shows the option was previously supported, but ignored.

src/dotnet/commands/dotnet-run/LocalizableStrings.cs

@@ -11,6 +11,8 @@ namespace Microsoft.DotNet.Tools.Run
 
         public const string CommandOptionProjectDescription = "The path to the project file to run (defaults to the current directory if there is only one project).";
 
+        public const string CommandOptionNoBuildDescription = "Skip building the project prior to running. By default, the project will be built.";
+
         public const string RunCommandException = "The build failed. Please fix the build errors and run again.";
 
         public const string RunCommandExceptionUnableToRun = "Unable to run your project\nPlease ensure you have a runnable project type and ensure '{0}' supports this project.\nThe current {1} is '{2}'";

src/dotnet/commands/dotnet-run/RunCommandParser.cs

@@ -31,6 +31,10 @@ namespace Microsoft.DotNet.Cli
                 Create.Option(
                     "-p|--project",
                     LocalizableStrings.CommandOptionProjectDescription,
-                    Accept.ExactlyOneArgument()));
+                    Accept.ExactlyOneArgument()),
+                Create.Option(
+                    "--no-build",
+                    LocalizableStrings.CommandOptionNoBuildDescription,
+                    Accept.NoArguments().ForwardAs("/p:NoBuild=true")));
     }
-}
+}