Github workflow problem with no details on error

Question

I'm new to Github workflows. I wanted to do a POC/demo showing code coverage and gating. I'm trying to fix two issues:

1. Get past the code coverage issue (the previous run worked)
2. Make a low coverage un-mergable into the master branch. I don't know how to raise some sort of blocking Github status. I request enlightenment on this.

Details:

If I do

mvn test

I get a build that works and has 100% code coverage (it says anyway).

When I check this into Github, the PR has an error, but no explanation.

Run madrapps/jacoco-report@v1.2
  with:
    paths: /home/runner/work/java-testing-demo/java-testing-demo/target/site/jacoco/jacoco.xml
    token: ***
    min-coverage-overall: 40
    min-coverage-changed-files: 85
    debug-mode: false
  env:
    JAVA_HOME: /opt/hostedtoolcache/Java_Adopt_jdk/17.0.2-8/x64
Event is push
base sha: 736b95e6068cb7a507790dfc01c6b44d9b663e67
head sha: 0a796a06c68a47511db88838b9d7794df9777535

build.yml:

name: Build

on: 
  push:
    branches:
      - "*"

  pull_request:
    branches:
      - master


jobs:
  build:
    environment: DEV
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
        with:
          fetch-depth: 0
      - name: Set up JDK 17
        uses: actions/setup-java@v3
        with:
          java-version: '17'
          distribution: 'adopt'
      - name: Cache SonarCloud packages
        uses: actions/cache@v1
        with:
          path: ~/.sonar/cache
          key: ${{ runner.os }}-sonar
          restore-keys: ${{ runner.os }}-sonar
      - name: Cache Maven packages
        uses: actions/cache@v1
        with:
          path: ~/.m2
          key: ${{ runner.os }}-m2-${{ hashFiles('**/pom.xml') }}
          restore-keys: ${{ runner.os }}-m2
      - name: Build and analyze
        run: |
          mvn -B verify org.sonarsource.scanner.maven:sonar-maven-plugin:sonar \
            -Dsonar.projectKey=bpracht_java-testing-demo \
            -Dsonar.organization=bpracht \
            -Dsonar.host.url=https://sonarcloud.io \
            -Dsonar.login="${{secrets.SONAR_TOKEN}}"
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}  # Needed to get PR information, if any
          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
      - name: Code coverage metric
        id: jacoco
        uses: madrapps/jacoco-report@v1.2
        with:
            paths: ${{ github.workspace }}/target/site/jacoco/jacoco.xml
            token: ${{ secrets.GITHUB_TOKEN }}
            min-coverage-overall: 40
            min-coverage-changed-files: 85            
      - name: Get the Coverage information
        run: |
          echo "Total coverage ${{ steps.jacoco.outputs.coverage-overall }}"
          echo "Changed Files coverage ${{ steps.jacoco.outputs.coverage-changed-files }}"

Answer 1

The default mvn wrapper scipts run the java program with an "exec" command. If anything fails, you do not get any detailed messaging at all and it skips any further steps in your actions list so you cannot even get access to the artifact files if you collect them.

To figure out what is going on you can remove the "exec" that prefixes the java command in the script and add "exit 0" as the last line in the maven script so that Github actions thinks everything was fine and you can then upload artifact files to help identifying the issue. You can also pipe all Maven output to a file then upload the log as an artifact. Your script would look something like this:

name: Java CI
on: [pull_request]
jobs:
  build:
    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      matrix:
        java_version: [8, 11, 13, 17]
        os: [windows-latest, ubuntu-latest]
    steps:
      - name: Checkout
        uses: actions/checkout@v2
      - name: Set up JDK ${{ matrix.java_version }}
        uses: actions/setup-java@v2
        with:
          java-version: ${{ matrix.java_version }}
          distribution: 'adopt'
      - name: Make Maven Wrapper and Java finder executable so command works for windows and nix
        if: contains(matrix.os, 'win') == false
        run: |
             chmod +x ./mvnw
      - name: Build with Maven
        run: |
             ./mvnw clean test -e --debug --file pom.xml --log-file maven.log
      - name: Archive logs
        uses: actions/upload-artifact@v3
        with:
          name: execution-logs-${{ matrix.java_version }}-${{ matrix.os }}
          path: maven.log
          retention-days: 1

You can then download the maven.log file from the artifact store for your project in Github