cache ruby 2.6 build (#216)

.github/workflows/2.6.yml

@@ -16,6 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+    - run: git submodule init && git submodule update
     - uses: actions-rs/cargo@v1
     - uses: actions/cache@v2
       with:
@@ -25,6 +26,11 @@ jobs:
           target
           librubyfmt/target
         key: ${{ runner.os }}-cargo-${{ hashFiles('**/Cargo.lock') }}
+    - uses: actions/cache@v2
+      with:
+        path: |
+          librubyfmt/ruby_checkout/ruby-2.6.6
+        key: ${{ runner.os }}-ruby26-full
     - uses: actions/setup-ruby@v1.0.0
       with:
         version: 2.6

build.rs

@@ -1,4 +1,5 @@
 fn main() {
+    // this is wild
     #[cfg(target_os = "macos")]
     {
         println!("cargo:rustc-link-lib=framework=foundation");

src/main.rs

@@ -116,6 +116,11 @@ fn main() {
         panic!("bad init status");
     }
     let args: Vec<String> = std::env::args().collect();
+    if args.len() >= 2 && (args[1] == "--help" || args[1] == "-h") {
+        eprintln!("{}", include_str!("../README.md"));
+        exit(1);
+    }
+
     if args.len() == 1 {
         // consume stdin
         let mut buffer = String::new();