Bootstrap packer config.rs for clean CI checkouts

Author: kexuejin

packer/build.rs

@@ -0,0 +1,36 @@
+use std::env;
+use std::fs;
+use std::path::PathBuf;
+
+fn main() {
+    let manifest_dir = env::var("CARGO_MANIFEST_DIR").expect("CARGO_MANIFEST_DIR missing");
+    let src_dir = PathBuf::from(manifest_dir).join("src");
+    let generated = src_dir.join("config.rs");
+    let defaults = src_dir.join("config.defaults.rs");
+
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed={}", defaults.display());
+    println!("cargo:rerun-if-changed={}", generated.display());
+
+    if generated.exists() {
+        return;
+    }
+
+    if !defaults.exists() {
+        panic!(
+            "Missing fallback template for config.rs: {}",
+            defaults.display()
+        );
+    }
+
+    fs::copy(&defaults, &generated).unwrap_or_else(|error| {
+        panic!(
+            "Failed to bootstrap {} from {}: {}",
+            generated.display(),
+            defaults.display(),
+            error
+        )
+    });
+
+    println!("cargo:warning=Bootstrapped config.rs from config.defaults.rs");
+}

packer/src/config.defaults.rs

@@ -0,0 +1,7 @@
+// Fallback config used when generated config.rs is absent in clean CI checkout.
+// pack.py overwrites src/config.rs with generated key material during packing.
+
+#[inline(always)]
+pub fn get_aes_key() -> [u8; 32] {
+    [0u8; 32]
+}