git buildpack no pipeline defined for kind pullrequest

[afewellvmware]

git buildpack errors on pullrequest pipeline if no override or pullrequest pipeline added in jenkins-x.yml file.

I am using jenkins-x with tekton on k8s:

NAME               VERSION
jx                 2.0.1185
Kubernetes cluster v1.14.10-gke.27
kubectl            v1.17.2
helm client        Client: v2.14.3+g0e7f3b6
git                2.17.1
Operating System   Ubuntu 18.04.3 LTS

If I use a jenkins-x.yml file with git buildpack and no overrides/pullrequest steps defined, I get the following error:
failed to generate Tekton CRDs: unable to extract the requested pipeline: no pipeline defined for kind pullrequest

I have tried this on several repos, brand new repos with a single-line jenkins-x.yml with one line buildPack: git, I also had repos already working with the git buildpack but with a override set for the pullRequest pipeline, in which case it works with no problem. But I made a change to my standard pipeline for several repos, which uses the git buildpack and a custom pullRequest pipeline step ... I moved my custom command from the pullRequest pipeline to the release pipeline and so my resulting jenkins-x.yml file only defined a release pipeline step. Once I made that change, the pipelines stopped working and started producing the error above.

I then added a placeholder step for the pullrequest pipeline to my jenkins-x.yml file, and the pipeline started working again.

So it appears if I do not have some step defined for the pullRequest pipeline when in a jenkins-x.yml file using the git buildpack, it will not find a default pullRequest pipe and will produce the above error.

Here is my currently working jenkins-x.yml file with a placeholder step for the pullrequest pipeline:

buildPack: git
pipelineConfig:
  pipelines:
    pullRequest:
      postBuild:
        steps:
        - command: echo "echo from the pullRequest postBuild pipeline step"   
    release:
      postBuild:
        steps:
        - command: ./pipescripts/post-merge-run.sh