Pass --frozen to cargo to ensure ./y.rs prepare fetches all deps

.github/workflows/nightly-cranelift.yml

@@ -36,6 +36,8 @@ jobs:
 
         cat Cargo.toml
 
+        cargo fetch
+
     - name: Build without unstable features
       # This is the config rust-lang/rust uses for builds
       run: ./y.rs build --no-unstable-features

build_system/utils.rs

@@ -111,7 +111,8 @@ fn base_cmd(&self, command: &str, cargo: &Path, dirs: &Dirs) -> Command {
             .arg("--manifest-path")
             .arg(self.manifest_path(dirs))
             .arg("--target-dir")
-            .arg(self.target_dir(dirs));
+            .arg(self.target_dir(dirs))
+            .arg("--frozen");
 
         cmd
     }