build(bindings/java): support explicit cargo build target

.github/workflows/bindings_java.yml

@@ -70,14 +70,9 @@ jobs:
       - name: Set up JDK 8
         uses: actions/setup-java@v3
         with:
-          distribution: 'temurin'
+          distribution: 'zulu'
           java-version: '8'
           cache: 'maven'
-      - name: Install Protoc
-        uses: arduino/setup-protoc@v2
-        with:
-          version: "23.4"
-          repo-token: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and test
         working-directory: bindings/java
         # `mvn install` and `mvn artifact:compare` are required to verify reproducible builds:

bindings/java/.cargo/config

@@ -0,0 +1,11 @@
+# See also https://github.com/rust-lang/rust/issues/44991
+
+[target.x86_64-unknown-linux-musl]
+rustflags = [
+    "-C", "target-feature=-crt-static",
+]
+
+[target.aarch64-unknown-linux-musl]
+rustflags = [
+    "-C", "target-feature=-crt-static",
+]

bindings/java/pom.xml

@@ -55,6 +55,7 @@
         <!-- customized properties -->
         <cargo-build.profile>dev</cargo-build.profile>
         <cargo-build.features>default</cargo-build.features>
+        <cargo-build.target/> <!-- override cargo build target; e.g., use musl instead -->
         <jni.classifier>${os.detected.classifier}</jni.classifier>
 
         <!-- library dependencies -->
@@ -177,6 +178,8 @@
                                 <argument>${project.basedir}/tools/build.py</argument>
                                 <argument>--classifier</argument>
                                 <argument>${jni.classifier}</argument>
+                                <argument>--target</argument>
+                                <argument>${cargo-build.target}</argument>
                                 <argument>--profile</argument>
                                 <argument>${cargo-build.profile}</argument>
                                 <argument>--features</argument>

bindings/java/tools/build.py

@@ -17,7 +17,7 @@
 # under the License.
 
 
-from argparse import ArgumentDefaultsHelpFormatter, ArgumentParser, BooleanOptionalAction
+from argparse import ArgumentDefaultsHelpFormatter, ArgumentParser
 from pathlib import Path
 import shutil
 import subprocess
@@ -52,6 +52,7 @@ def get_cargo_artifact_name(classifier: str) -> str:
 
     parser = ArgumentParser(formatter_class=ArgumentDefaultsHelpFormatter)
     parser.add_argument('--classifier', type=str, required=True)
+    parser.add_argument('--target', type=str, default='')
     parser.add_argument('--profile', type=str, default='dev')
     parser.add_argument('--features', type=str, default='default')
     args = parser.parse_args()
@@ -61,12 +62,15 @@ def get_cargo_artifact_name(classifier: str) -> str:
     if args.features:
         cmd += ['--features', args.features]
 
-    target = classifier_to_target(args.classifier)
-    if target:
-        command = ['rustup', 'target', 'add', target]
-        print('$ ' + subprocess.list2cmdline(command))
-        subprocess.run(command, cwd=basedir, check=True)
-        cmd += ['--target', target]
+    if args.target:
+        target = args.target
+    else:
+        target = classifier_to_target(args.classifier)
+
+    command = ['rustup', 'target', 'add', target]
+    print('$ ' + subprocess.list2cmdline(command))
+    subprocess.run(command, cwd=basedir, check=True)
+    cmd += ['--target', target]
 
     output = basedir / 'target' / 'bindings'
     Path(output).mkdir(exist_ok=True, parents=True)