fixup! Josh preparations

clippy_dev/src/sync.rs

@@ -60,9 +60,10 @@ fn start_josh() -> impl Drop {
     Josh(josh)
 }
 
-fn rustc_version() -> String {
+fn rustc_hash(version: Option<String>) -> String {
     let version = String::from_utf8(
         process::Command::new("rustc")
+            .arg(format!("+{}", version.unwrap_or_default()))
             .arg("--version")
             .arg("--verbose")
             .output()
@@ -112,7 +113,7 @@ pub fn rustc_pull() {
         .run()
         .expect("FAILED to commit rust-toolchain file, something went wrong");
 
-    let commit = rustc_version();
+    let commit = rustc_hash(Some(format!("nightly-{date}")));
 
     // Make sure josh is running in this scope
     {
@@ -178,7 +179,7 @@ pub fn rustc_push(rustc_path: String, github_user: String) {
     // Prepare the branch. Pushing works much better if we use as base exactly
     // the commit that we pulled from last time, so we use the `rustc --version`
     // to find out which commit that would be.
-    let base = rustc_version();
+    let base = rustc_hash(None);
 
     println!("Preparing {github_user}/rust (base: {base})...");
     sh.change_dir(rustc_path);