only rebuild on submodule-commit change

Author: 0xbrayo

.github/workflows/build-only.yml

@@ -27,14 +27,19 @@ jobs:
       run: |
         echo "RELEASE=${{ startsWith(github.ref_name, 'v') }}" >> $GITHUB_ENV
 
+    - name: Get aw-server-rust submodule commit
+      id: submodule-commit
+      run: |
+        echo "commit=$(git rev-parse HEAD:aw-server-rust)" >> $GITHUB_OUTPUT
+
     - name: Cache JNI libs
       uses: actions/cache@v3
       id: cache-jniLibs
       env:
         cache-name: jniLibs
       with:
         path: mobile/src/main/jniLibs/
-        key: ${{ env.cache-name }}-release-${{ env.RELEASE }}-ndk-${{ env.NDK_VERSION }}-${{ hashFiles('.git/modules/aw-server-rust/HEAD') }}
+        key: ${{ env.cache-name }}-release-${{ env.RELEASE }}-ndk-${{ env.NDK_VERSION }}-${{ steps.submodule-commit.outputs.commit }}
 
     - name: Display structure of downloaded files
       if: steps.cache-jniLibs.outputs.cache-hit == 'true'
@@ -148,6 +153,11 @@ jobs:
         ls $ANDROID_NDK_HOME
         echo "ANDROID_NDK_HOME=$ANDROID_NDK_HOME" >> $GITHUB_ENV
 
+    - name: Get aw-server-rust submodule commit
+      id: submodule-commit
+      run: |
+        echo "commit=$(git rev-parse HEAD:aw-server-rust)" >> $GITHUB_OUTPUT
+
     # Restores jniLibs from cache
     # `actions/cache/restore` only restores, without saving back in a post-hook
     - uses: actions/cache/restore@v3
@@ -156,7 +166,7 @@ jobs:
         cache-name: jniLibs
       with:
         path: mobile/src/main/jniLibs/
-        key: ${{ env.cache-name }}-release-${{ env.RELEASE }}-ndk-${{ env.NDK_VERSION }}-${{ hashFiles('.git/modules/aw-server-rust/HEAD') }}
+        key: ${{ env.cache-name }}-release-${{ env.RELEASE }}-ndk-${{ env.NDK_VERSION }}-${{ steps.submodule-commit.outputs.commit }}
         fail-on-cache-miss: true
 
     - name: Check that jniLibs present