You can find the state of any CI pipeline in the CI/CD entry of the project page. When you click that, you'll see a list of all pipelines and their statuses:
If tests have failed, clicking on "run_pipeline" will give you details about exactly what has failed and why.
2.2 If you aren't sure what went wrong, click on the "failed" icon under Status. That will show you a complete log of everything that happened. In addition, on the right hand side of the screen, you'll see "Job Artifacts." From there, you can browse and see all of the Logger output the various tests generated. If you need to add temporary debug output (because the pipeline doesn't fail on your machine, but it does fail in CI), you can use the LoggerManager to create the output and you'll find it in those artifacts.