- Revert a few unnecessary changes.

- Add -e for Maven to see why it failed on last build.

Author: vonnieda

.github/workflows/build.yml

@@ -111,7 +111,7 @@ jobs:
             # Peform a test build in the host repo, which now contains all of the
             # build artifacts.
             cd /host_repo
-            mvn -B test
+            mvn -e -B test
 
       - name: Upload Artifacts
         uses: actions/upload-artifact@v2
@@ -125,7 +125,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-18.04]
-        java: [8]
+        java: [15]
 
     runs-on: ${{ matrix.os }}
 
@@ -195,7 +195,7 @@ jobs:
               -D BUILD_opencv_gapi=OFF \
               -D CMAKE_BUILD_TYPE=RELEASE \
               ..
-            make -j8
+            make -j4
 
             # Copy the build artifacts to the /artifacts directory, which will be
             # used by the host to upload them.
@@ -300,7 +300,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-18.04]
-        java: [8]
+        java: [15]
 
     runs-on: ${{ matrix.os }}