build both editions of the book

Author: steveklabnik

src/bootstrap/doc.rs

@@ -53,6 +53,11 @@ pub fn rustbook(build: &Build, target: &str, name: &str) {
                    .arg(out));
 }
 
+pub fn book(build: &Build, target: &str, name: &str) {
+    rustbook(build, target, &format!("{}/first-edition", name));
+    rustbook(build, target, &format!("{}/second-edition", name));
+}
+
 /// Generates all standalone documentation as compiled by the rustdoc in `stage`
 /// for the `target` into `out`.
 ///

src/bootstrap/step.rs

@@ -581,7 +581,7 @@ pub fn build_rules<'a>(build: &'a Build) -> Rules {
               .stage(0)
          })
          .default(build.config.docs)
-         .run(move |s| doc::rustbook(build, s.target, "book"));
+         .run(move |s| doc::book(build, s.target, "book"));
     rules.doc("doc-nomicon", "src/doc/nomicon")
          .dep(move |s| {
              s.name("tool-rustbook")