bootstrap: improve 'build --help' by explaining what exactly the last example does

diff --git a/src/bootstrap/flags.rs b/src/bootstrap/flags.rs
index f100baa5d2ca7181be6fc4f93847ef5a8439b97b..3a265b2f3bbb78b68cf4909f893ab99f9a38810a 100644 (file)
--- a/src/bootstrap/flags.rs
+++ b/src/bootstrap/flags.rs
@@ -198,7 +198,11 @@ pub fn parse(args: &[String]) -> Flags {
 
     For a quick build with a usable compile, you can pass:
 
-        ./x.py build --stage 1 src/libtest");
+        ./x.py build --stage 1 src/libtest
+
+    This will first build everything once (like --stage 0 without further
+    arguments would), and then use the compiler built in stage 0 to build
+    src/libtest and its dependencies.");
             }
             "test" => {
                 subcommand_help.push_str("\n