Use build.rs to generate empty snapshot

.github/workflows/rust.yml

@@ -14,8 +14,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v3
-    - name: Prebuild
-      run: touch RUNTIME_SNAPSHOT.bin
     - name: Build
       run: cargo build --verbose
     - name: Run tests

build.rs

@@ -0,0 +1,19 @@
+use std::env;
+use std::fs::File;
+use std::path::PathBuf;
+
+const RUNTIME_SNAPSHOT_PATH: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/target/RUNTIME_SNAPSHOT.bin");
+
+fn main () {
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=src/ext/*");
+    println!("cargo:rerun-if-changed=src/runtime.rs");
+    println!("cargo:rerun-if-changed=src/extensions.rs");
+
+    let path = PathBuf::from(RUNTIME_SNAPSHOT_PATH);
+
+    // Create the file if it doesn't exist
+    if !path.exists() {
+        File::create(&path).unwrap();
+    }
+}

src/runtime.rs

@@ -20,7 +20,7 @@ use log::debug;
 const USER_AGENT: &str = "OpenWorkers/0.1.0";
 
 static RUNTIME_SNAPSHOT: &[u8] =
-    include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/RUNTIME_SNAPSHOT.bin"));
+    include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/target/RUNTIME_SNAPSHOT.bin"));
 
 pub fn module_url(path_str: &str) -> Url {
     let current_dir = std::env::current_dir().unwrap();

src/snapshot.rs

@@ -9,7 +9,7 @@ use std::env;
 use std::path::PathBuf;
 use std::fs::File;
 
-const RUNTIME_SNAPSHOT_PATH: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/RUNTIME_SNAPSHOT.bin");
+const RUNTIME_SNAPSHOT_PATH: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/target/RUNTIME_SNAPSHOT.bin");
 
 pub fn create_runtime_snapshot() {
     println!("Building snapshot");