Enable debug logging to get problem on JDK 15

Author: oliemansm

.github/workflows/gradle.yml

@@ -24,12 +24,21 @@ jobs:
         uses: actions/setup-java@v1
         with:
           java-version: ${{ matrix.java }}
+      - name: Cache Gradle
+        uses: actions/cache@v2
+        with:
+          path: |
+            ~/.gradle/caches
+            ~/.gradle/wrapper
+          key: ${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*') }}
+          restore-keys: |
+            ${{ runner.os }}-gradle-
       - name: Make gradlew executable (non-Windows only)
         if: matrix.os != 'windows-latest'
         run: chmod +x ./gradlew
       - name: Gradle Check (non-Windows)
         if: matrix.os != 'windows-latest'
-        run: ./gradlew --info check
+        run: ./gradlew --info --stacktrace check
       - name: Gradle Check (Windows)
         if: matrix.os == 'windows-latest'
         shell: cmd