---
apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: matrixed-pipeline-with-err
spec:
    tasks:
      - name: echo-result
        taskSpec:
          results:
            - name: output
              type: string
          steps:
            - name: emit-a-result
              image: mirror.gcr.io/bash
              script: |
                #!/usr/bin/env bash
                echo -n "some data" | tee $(results.output.path)
      - name: consume-result
        matrix:
          params:
            - name: version
              value: ["1", "2"]
        params:
          - name: bad-input
            value: "$(tasks)-$(tasks.echo-result.results.output)"
        taskSpec:
          params:
            - name: bad-input
          steps:
            - name: consume-the-result
              image: mirror.gcr.io/bash
              script: |
                #!/usr/bin/env bash
                echo -n "input: $(params.bad-input)"

$  kubectl apply -f bad-task-ref.yaml
Error from server (InternalError): error when creating "bad-task-ref.yaml": Internal error occurred: failed calling webhook "validation.webhook.pipeline.tekton.dev": failed to call webhook: Post "https://tekton-pipelines-webhook.tekton-pipelines.svc:443/resource-validation?timeout=10s": EOF 

{"severity":"error","timestamp":"2025-10-30T13:40:19.534Z","logger":"tekton-pipelines-webhook","caller":"webhook/webhook.go:254","message":"http: panic serving 10.244.0.1:35163: runtime error: index out of range [1] with length 1\ngoroutine 1668181 [running]:\nnet/http.(*conn).serve.func1()\n\tnet/http/server.go:1947 +0xbe\npanic({0x23d0ba0?, 0xc0018bc150?})\n\truntime/panic.go:792 +0x132\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.validateMatrixedPipelineTaskConsumed({0xc00184dc40?, 0x9?, 0x2573af0?}, 0xc000afb138)\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:816 +0x377\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.findAndValidateResultRefsForMatrix({0xc0010a7c00?, 0xc000afb138?, 0xc000afaf80?}, 0xc000afb138)\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:798 +0x232\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.validateTaskResultsFromMatrixedPipelineTasksConsumed({0xc0010a7c00, 0x2, 0x2})\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:834 +0x1a5\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.validateMatrix({0x290bad0, 0xc0018583c0}, {0xc0010a7c00, 0x2, 0x2})\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:786 +0x13e\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.(*PipelineSpec).Validate(0xc0010a7b48, {0x290bad0, 0xc0018583c0})\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:96 +0x7f6\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.(*Pipeline).Validate(0xc0010a7a40, {0x290bad0, 0xc001858390})\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:60 +0xa7\nknative.dev/pkg/webhook/resourcesemantics/validation.validate({0x290bad0, 0xc001858390}, {0x290b520, 0xc0010a7a40}, 0xc000d6f1e0)\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/resourcesemantics/validation/validation_admit.go:183 +0x115\nknative.dev/pkg/webhook/resourcesemantics/validation.(*reconciler).Admit(0xc00035ac30, {0x290bad0?, 0xc001858000?}, 0xc000d6f1e0)\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/resourcesemantics/validation/validation_admit.go:79 +0x1ad\nknative.dev/pkg/webhook.New.admissionHandler.func4({0x28f75c8, 0xc0001e9960}, 0xc001b52280)\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/admission.go:123 +0x53b\nnet/http.HandlerFunc.ServeHTTP(0xc0006383a8?, {0x28f75c8?, 0xc0001e9960?}, 0x68299f?)\n\tnet/http/server.go:2294 +0x29\nnet/http.(*ServeMux).ServeHTTP(0xc00182dd70?, {0x28f75c8, 0xc0001e9960}, 0xc001b52280)\n\tnet/http/server.go:2822 +0x1c4\nknative.dev/pkg/webhook.(*Webhook).ServeHTTP(0xc000638300, {0x28f75c8, 0xc0001e9960}, 0xc001b52280)\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/webhook.go:337 +0xad\nknative.dev/pkg/network/handlers.(*Drainer).ServeHTTP(0xc000579340, {0x28f75c8, 0xc0001e9960}, 0xc001b52280)\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/network/handlers/drain.go:113 +0x150\nnet/http.serverHandler.ServeHTTP({0x28e78e8?}, {0x28f75c8?, 0xc0001e9960?}, 0x1?)\n\tnet/http/server.go:3301 +0x8e\nnet/http.(*conn).serve(0xc001800990, {0x290bad0, 0xc00061ea80})\n\tnet/http/server.go:2102 +0x625\ncreated by net/http.(*Server).Serve in goroutine 120\n\tnet/http/server.go:3454 +0x485\n","commit":"eaf7dc1","stacktrace":"knative.dev/pkg/webhook.(*zapWrapper).Write\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/webhook.go:254\nlog.(*Logger).output\n\tlog/log.go:245\nlog.(*Logger).Printf\n\tlog/log.go:268\nnet/http.(*Server).logf\n\tnet/http/server.go:3638\nnet/http.(*conn).serve.func1\n\tnet/http/server.go:1948\nruntime.gopanic\n\truntime/panic.go:792\nruntime.goPanicIndex\n\truntime/panic.go:115\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.validateMatrixedPipelineTaskConsumed\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:816\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.findAndValidateResultRefsForMatrix\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:798\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.validateTaskResultsFromMatrixedPipelineTasksConsumed\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:834\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.validateMatrix\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:786\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.(*PipelineSpec).Validate\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:96\ngithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1.(*Pipeline).Validate\n\tgithub.com/tektoncd/pipeline/pkg/apis/pipeline/v1beta1/pipeline_validation.go:60\nknative.dev/pkg/webhook/resourcesemantics/validation.validate\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/resourcesemantics/validation/validation_admit.go:183\nknative.dev/pkg/webhook/resourcesemantics/validation.(*reconciler).Admit\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/resourcesemantics/validation/validation_admit.go:79\nknative.dev/pkg/webhook.New.admissionHandler.func4\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/admission.go:123\nnet/http.HandlerFunc.ServeHTTP\n\tnet/http/server.go:2294\nnet/http.(*ServeMux).ServeHTTP\n\tnet/http/server.go:2822\nknative.dev/pkg/webhook.(*Webhook).ServeHTTP\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/webhook/webhook.go:337\nknative.dev/pkg/network/handlers.(*Drainer).ServeHTTP\n\tknative.dev/pkg@v0.0.0-20250415155312-ed3e2158b883/network/handlers/drain.go:113\nnet/http.serverHandler.ServeHTTP\n\tnet/http/server.go:3301\nnet/http.(*conn).serve\n\tnet/http/server.go:2102"} 

kubectl apply -f bad-task-ref.yaml
pipeline.tekton.dev/matrixed-pipeline-with-err created