GitHub action fails with exit code 1 when echo statement is removed

I have a GitHub action step which looks like this:

      - if: ${{ steps.cache-images.outputs.cache-hit == 'true' }}
        name: Load saved docker images
        run: |
          if [[ -f docker-images-backup/apisix-images.tar ]]; then
            [[ ${{ steps.test_env.outputs.type }} != first ]] && sudo ./ci/init-${{ steps.test_env.outputs.type }}-test-service.sh before
            docker load --input docker-images-backup/apisix-images.tar
            make ci-env-up project_compose_ci=ci/pod/docker-compose.${{ steps.test_env.outputs.type }}.yml
            echo "loaded docker images"
            echo test_type:
            [[ ${{ steps.test_env.outputs.type }} != first ]] && sudo ./ci/init-${{ steps.test_env.outputs.type }}-test-service.sh after && echo "executed"
          fi
          echo "exited if"

Which fails consistently (with exit code 1) if I remove the last echo statement that I added to debug the same error.

I have tried running the script locally with different combinations of values of the variables in this script but it works perfectly fine.

I have studied a little about segfaults in c programming occcuring when removing/adding a print statement. I don't think this is a similar case but I wonder if shell scripting has similar kind of hazard.

So it turns out that GitHub actions evaluate the exit code when a step is executed completely. When the value of ${{ steps.test_env.outputs.type }} is first then [[ ${{ steps.test_env.outputs.type }} != first ]] results in a non-zero exit code (exit code 1). Due to this, the GitHub action fails with exit code 1.

When I add an echo statement at the end, the last exit code becomes zero (and the non-zero exit status due to the previous statement gets covered) due to this the action does not fail.

To fix this you can simply implement conditional execution of code using an if statement:

Replace:

[[ ${{ steps.test_env.outputs.type }} != first ]] && sudo ./ci/init-${{ steps.test_env.outputs.type }}-test-service.sh after && echo "executed"

With:

if [[ ${{ steps.test_env.outputs.type }} != first ]]; then
  sudo ./ci/init-${{ steps.test_env.outputs.type }}-test-service.sh after
fi