Pin rust, stub libunwind

Author: abaker

.github/workflows/build.yml

@@ -32,13 +32,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
-          targets: ${{ matrix.target }}
-
-      - uses: Swatinem/rust-cache@v2
-        with:
-          key: android-${{ matrix.target }}
+          target: ${{ matrix.target }}
+          cache-key: android-${{ matrix.target }}
 
       - name: Install pinned Android NDK
         run: echo y | $ANDROID_HOME/cmdline-tools/latest/bin/sdkmanager "ndk;21.3.6528147"
@@ -52,6 +49,11 @@ jobs:
         run: |
           triple_upper=$(echo "${{ matrix.target }}" | tr 'a-z-' 'A-Z_')
           export "CARGO_TARGET_${triple_upper}_LINKER=${{ matrix.cc }}"
+          # NDK r21d lacks libunwind.a but Rust's Android target spec requires
+          # it; empty stub satisfies the link, libgcc carries the real symbols.
+          mkdir -p "$RUNNER_TEMP/libunwind-stub"
+          printf '!<arch>\n' > "$RUNNER_TEMP/libunwind-stub/libunwind.a"
+          export RUSTFLAGS="-L $RUNNER_TEMP/libunwind-stub"
           cargo build --target ${{ matrix.target }} --release
 
       - name: Upload native lib
@@ -101,13 +103,10 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@stable
-        with:
-          targets: ${{ matrix.target }}
-
-      - uses: Swatinem/rust-cache@v2
+      - uses: actions-rust-lang/setup-rust-toolchain@v1
         with:
-          key: desktop-${{ matrix.target }}
+          target: ${{ matrix.target }}
+          cache-key: desktop-${{ matrix.target }}
 
       - name: Build
         shell: bash

rust-toolchain.toml

@@ -0,0 +1,2 @@
+[toolchain]
+channel = "1.95.0"