diff --git a/src/bootstrap/dist.rs b/src/bootstrap/dist.rs
index 05d59e7d59565..609802c4767e5 100644
--- a/src/bootstrap/dist.rs
+++ b/src/bootstrap/dist.rs
@@ -365,6 +365,9 @@ impl Step for Rustc {
         // tiny morsel of metadata is used by rust-packaging
         let version = build.rust_version();
         t!(t!(File::create(overlay.join("version"))).write_all(version.as_bytes()));
+        if let Some(sha) = build.rust_sha() {
+            t!(t!(File::create(overlay.join("git-commit-hash"))).write_all(sha.as_bytes()));
+        }
 
         // On MinGW we've got a few runtime DLL dependencies that we need to
         // include. The first argument to this script is where to put these DLLs
@@ -844,6 +847,9 @@ impl Step for PlainSourceTarball {
 
         // Create the version file
         write_file(&plain_dst_src.join("version"), build.rust_version().as_bytes());
+        if let Some(sha) = build.rust_sha() {
+            write_file(&plain_dst_src.join("git-commit-hash"), sha.as_bytes());
+        }
 
         // If we're building from git sources, we need to vendor a complete distribution.
         if build.rust_info.is_git() {
@@ -1157,6 +1163,9 @@ impl Step for Extended {
         install(&build.src.join("LICENSE-MIT"), &overlay, 0o644);
         let version = build.rust_version();
         t!(t!(File::create(overlay.join("version"))).write_all(version.as_bytes()));
+        if let Some(sha) = build.rust_sha() {
+            t!(t!(File::create(overlay.join("git-commit-hash"))).write_all(sha.as_bytes()));
+        }
         install(&etc.join("README.md"), &overlay, 0o644);
 
         // When rust-std package split from rustc, we needed to ensure that during
diff --git a/src/bootstrap/lib.rs b/src/bootstrap/lib.rs
index f21b382619d0a..67791e8758c0b 100644
--- a/src/bootstrap/lib.rs
+++ b/src/bootstrap/lib.rs
@@ -797,6 +797,11 @@ impl Build {
         self.rust_info.version(self, channel::CFG_RELEASE_NUM)
     }
 
+    /// Return the full commit hash
+    fn rust_sha(&self) -> Option<&str> {
+        self.rust_info.sha()
+    }
+
     /// Returns the `a.b.c` version that the given package is at.
     fn release_num(&self, package: &str) -> String {
         let mut toml = String::new();
diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
index e2be021e7cc39..0e91fa9c6022b 100644
--- a/src/tools/build-manifest/src/main.rs
+++ b/src/tools/build-manifest/src/main.rs
@@ -113,6 +113,7 @@ struct Manifest {
 #[derive(Serialize)]
 struct Package {
     version: String,
+    git_commit_hash: Option<String>,
     target: BTreeMap<String, Target>,
 }
 
@@ -167,6 +168,9 @@ struct Builder {
     rust_version: String,
     cargo_version: String,
     rls_version: String,
+    rust_git_commit_hash: Option<String>,
+    cargo_git_commit_hash: Option<String>,
+    rls_git_commit_hash: Option<String>,
 }
 
 fn main() {
@@ -194,6 +198,9 @@ fn main() {
         rust_version: String::new(),
         cargo_version: String::new(),
         rls_version: String::new(),
+        rust_git_commit_hash: None,
+        cargo_git_commit_hash: None,
+        rls_git_commit_hash: None,
     }.build();
 }
 
@@ -202,18 +209,16 @@ impl Builder {
         self.rust_version = self.version("rust", "x86_64-unknown-linux-gnu");
         self.cargo_version = self.version("cargo", "x86_64-unknown-linux-gnu");
         self.rls_version = self.version("rls", "x86_64-unknown-linux-gnu");
+        self.rust_git_commit_hash = self.git_commit_hash("rust", "x86_64-unknown-linux-gnu");
+        self.cargo_git_commit_hash = self.git_commit_hash("cargo", "x86_64-unknown-linux-gnu");
+        self.rls_git_commit_hash = self.git_commit_hash("rls", "x86_64-unknown-linux-gnu");
 
         self.digest_and_sign();
         let manifest = self.build_manifest();
-        let filename = format!("channel-rust-{}.toml", self.rust_release);
-        self.write_manifest(&toml::to_string(&manifest).unwrap(), &filename);
-
-        let filename = format!("channel-rust-{}-date.txt", self.rust_release);
-        self.write_date_stamp(&manifest.date, &filename);
+        self.write_channel_files(&self.rust_release, &manifest);
 
         if self.rust_release != "beta" && self.rust_release != "nightly" {
-            self.write_manifest(&toml::to_string(&manifest).unwrap(), "channel-rust-stable.toml");
-            self.write_date_stamp(&manifest.date, "channel-rust-stable-date.txt");
+            self.write_channel_files("stable", &manifest);
         }
     }
 
@@ -249,6 +254,7 @@ impl Builder {
 
         let mut pkg = Package {
             version: self.cached_version("rust").to_string(),
+            git_commit_hash: self.cached_git_commit_hash("rust").clone(),
             target: BTreeMap::new(),
         };
         for host in HOSTS {
@@ -342,6 +348,7 @@ impl Builder {
 
         dst.insert(pkgname.to_string(), Package {
             version: self.cached_version(pkgname).to_string(),
+            git_commit_hash: self.cached_git_commit_hash(pkgname).clone(),
             target: targets,
         });
     }
@@ -375,6 +382,16 @@ impl Builder {
         }
     }
 
+    fn cached_git_commit_hash(&self, component: &str) -> &Option<String> {
+        if component == "cargo" {
+            &self.cargo_git_commit_hash
+        } else if component == "rls" || component == "rls-preview" {
+            &self.rls_git_commit_hash
+        } else {
+            &self.rust_git_commit_hash
+        }
+    }
+
     fn version(&self, component: &str, target: &str) -> String {
         let mut cmd = Command::new("tar");
         let filename = self.filename(component, target);
@@ -382,14 +399,33 @@ impl Builder {
            .arg(self.input.join(&filename))
            .arg(format!("{}/version", filename.replace(".tar.gz", "")))
            .arg("-O");
-        let version = t!(cmd.output());
-        if !version.status.success() {
+        let output = t!(cmd.output());
+        if !output.status.success() {
             panic!("failed to learn version:\n\n{:?}\n\n{}\n\n{}",
                    cmd,
-                   String::from_utf8_lossy(&version.stdout),
-                   String::from_utf8_lossy(&version.stderr));
+                   String::from_utf8_lossy(&output.stdout),
+                   String::from_utf8_lossy(&output.stderr));
+        }
+        String::from_utf8_lossy(&output.stdout).trim().to_string()
+    }
+
+    fn git_commit_hash(&self, component: &str, target: &str) -> Option<String> {
+        let mut cmd = Command::new("tar");
+        let filename = self.filename(component, target);
+        cmd.arg("xf")
+           .arg(self.input.join(&filename))
+           .arg(format!("{}/git-commit-hash", filename.replace(".tar.gz", "")))
+           .arg("-O");
+        let output = t!(cmd.output());
+        if output.status.success() {
+            Some(String::from_utf8_lossy(&output.stdout).trim().to_string())
+        } else {
+            // This is always called after `.version()`.
+            // So if that didn’t fail but this does,
+            // that’s very probably because the tarball is valid
+            // but does not contain a `git-commit-hash` file.
+            None
         }
-        String::from_utf8_lossy(&version.stdout).trim().to_string()
     }
 
     fn hash(&self, path: &Path) -> String {
@@ -425,16 +461,16 @@ impl Builder {
         assert!(t!(child.wait()).success());
     }
 
-    fn write_manifest(&self, manifest: &str, name: &str) {
-        let dst = self.output.join(name);
-        t!(t!(File::create(&dst)).write_all(manifest.as_bytes()));
-        self.hash(&dst);
-        self.sign(&dst);
+    fn write_channel_files(&self, channel_name: &str, manifest: &Manifest) {
+        self.write(&toml::to_string(&manifest).unwrap(), channel_name, ".toml");
+        self.write(&manifest.date, channel_name, "-date.txt");
+        self.write(manifest.pkg["rust"].git_commit_hash.as_ref().unwrap(),
+                   channel_name, "-git-commit-hash.txt");
     }
 
-    fn write_date_stamp(&self, date: &str, name: &str) {
-        let dst = self.output.join(name);
-        t!(t!(File::create(&dst)).write_all(date.as_bytes()));
+    fn write(&self, contents: &str, channel_name: &str, suffix: &str) {
+        let dst = self.output.join(format!("channel-rust-{}{}", channel_name, suffix));
+        t!(t!(File::create(&dst)).write_all(contents.as_bytes()));
         self.hash(&dst);
         self.sign(&dst);
     }