fix(build): broken android target build caused by ndk upgrade

.github/workflows/android-armv7.yml

@@ -55,6 +55,12 @@ jobs:
       - name: 'Build TypeScript'
         run: yarn build
 
+      - uses: nttld/setup-ndk@v1
+        id: setup-ndk
+        with:
+          ndk-version: r21e
+          add-to-path: false
+
       - name: Cross build
         run: |
           export CARGO_TARGET_ARMV7_LINUX_ANDROIDEABI_LINKER="${ANDROID_NDK_HOME}/toolchains/llvm/prebuilt/linux-x86_64/bin/armv7a-linux-androideabi24-clang"

crates/build/src/android.rs

@@ -0,0 +1,16 @@
+use std::env;
+use std::fs;
+use std::io::{Error, Write};
+use std::path;
+
+// Workaround from https://github.com/rust-lang/rust/pull/85806#issuecomment-1096266946
+pub fn setup() -> Result<(), Error> {
+  let out_dir = env::var("OUT_DIR").expect("OUT_DIR not set");
+  let mut dist = path::PathBuf::from(&out_dir);
+  dist.push("libgcc.a");
+  let mut libgcc = fs::File::create(&dist)?;
+  libgcc.write(b"INPUT(-lunwind)")?;
+  drop(libgcc);
+  println!("cargo:rustc-link-search={}", &out_dir);
+  Ok(())
+}

crates/build/src/lib.rs

@@ -1,8 +1,13 @@
+mod android;
 mod macos;
 
 pub fn setup() {
   println!("cargo:rerun-if-env-changed=DEBUG_GENERATED_CODE");
-  if let Ok("macos") = std::env::var("CARGO_CFG_TARGET_OS").as_deref() {
-    macos::setup();
+  match std::env::var("CARGO_CFG_TARGET_OS").as_deref() {
+    Ok("macos") => {
+      macos::setup();
+    }
+    Ok("android") => if let Ok(_) = android::setup() {},
+    _ => {}
   }
 }