#2 save maven caches on build failure

.github/workflows/build.yml

@@ -41,7 +41,6 @@ jobs:
       - name: Load m2 repository cache # Manually caching .m2 repo as the setup-java caching isn't falling back to older caches
         id: cached-m2-repo
         uses: actions/cache@v4
-        if: always()
         with:
           path: ~/.m2/repository
           key: maven-${{ hashFiles('**/pom.xml') }}
@@ -50,7 +49,6 @@ jobs:
       - name: Load m2 build cache
         id: cached-m2-build
         uses: actions/cache@v4
-        if: always()
         with:
           path: ~/.m2/build-cache
           key: maven-build-cache-${{ hashFiles('**/pom.xml') }}
@@ -79,6 +77,23 @@ jobs:
           ./get_helm.sh
       - name: Build aiSSEMBLE
         run: ./mvnw -B clean install --file pom.xml -Dhabushu.usePyenv=false -Pci
+      #NB: The following two explicit cache saves are necessary to ensure caches are saved on build failure, until
+      # https://github.com/actions/cache/issues/1315 is resolved
+      - name: Save m2 repository cache
+        id: save-m2-repo
+        uses: actions/cache/save@v4
+        if: always()
+        with:
+          path: ~/.m2/repository
+          key: maven-${{ hashFiles('**/pom.xml') }}
+      - name: Save m2 build cache
+        id: save-m2-build
+        uses: actions/cache/save@v4
+        if: always()
+        with:
+          path: ~/.m2/build-cache
+          key: maven-build-cache-${{ hashFiles('**/pom.xml') }}
+
 
 #      # Optional: Uploads the full dependency graph to GitHub to improve the quality of Dependabot alerts this repository can receive
 #      - name: Update dependency graph