image-digest-exporter step appears out of order with its position in pod

[ghost]

Expected Behavior

The image-digest-exporter Step should appear after all of the user's Steps in a TaskRun's status.steps list.

Actual Behavior

In https://dashboard.dogfooding.tekton.dev/#/namespaces/default/pipelineruns/pipeline-release-nightly-zf2lz?pipelineTask=publish-images&step=image-digest-exporter-vcqhc we see the image-digest-exporter sorted out of order, appearing before user-created Steps copy-to-latest-bucket, tag-images and run-ko.

In that example the tag-images Step was the first to fail but due to misordering of the steps' statuses it appears that the image-digest-exporter was the original failure. This confuses several subsequent things:

1. The TaskRun gets the wrong Succeeded condition, claiming that the image-digest-exporter was the original failure.

2. The dashboard similarly shows image-digest-exporter as the source of failure:

   

3. The dashboard also shows that the actual failing Step (tag-images in this case) was "Not Run", which is incorrect.

Additional Info

• Resources Involved

I've captured both the TaskRun's status field from the dashboard as well as the full Pod yaml for that TaskRun in this gist.

• Kubernetes version:

Client Version: version.Info{Major:"1", Minor:"18", GitVersion:"v1.18.2", GitCommit:"52c56ce7a8272c798dbc29846288d7cd9fbae032", GitTreeState:"clean", BuildDate:"2020-04-16T11:56:40Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"darwin/amd64"}
Server Version: version.Info{Major:"1", Minor:"17+", GitVersion:"v1.17.14-gke.1600", GitCommit:"7c407f5cc8632f9af5a2657f220963aa7f1c46e7", GitTreeState:"clean", BuildDate:"2020-12-07T09:22:27Z", GoVersion:"go1.13.15b4", Compiler:"gc", Platform:"linux/amd64"}

• Tekton Pipeline version:

v0.18.1