Merge branch 'beta-prerelease' of https://github.com/cuviper/rust into rollup

Author: alexcrichton

src/bootstrap/lib.rs

@@ -771,7 +771,11 @@ impl Build {
     fn release(&self, num: &str) -> String {
         match &self.config.channel[..] {
             "stable" => num.to_string(),
-            "beta" => format!("{}-beta.{}", num, self.beta_prerelease_version()),
+            "beta" => if self.rust_info.is_git() {
+                format!("{}-beta.{}", num, self.beta_prerelease_version())
+            } else {
+                format!("{}-beta", num)
+            },
             "nightly" => format!("{}-nightly", num),
             _ => format!("{}-dev", num),
         }