workflow-running-forever.yaml

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: test-
  namespace: argo
spec:
  entrypoint: reproduce

  arguments:
    parameters:
      - name: items
        value: |
          [ "1", "2", "3", "4" ]

# Steps

  templates:

    - name: reproduce
      steps:
        - - name: step1
            template: sub-steps
            arguments:
              parameters:
                - name: cluster
                  value: "{{item}}"
            withParam: "{{workflow.parameters.items}}"
        - - name: step2
            template: sub-steps
            arguments:
              parameters:
                - name: cluster
                  value: "{{item}}"
            withParam: "{{workflow.parameters.items}}"

    - name: sub-steps
      steps:
        - - name: foo
            template: exec
        - - name: bar
            template: exec
        - - name: baz
            template: exec

# Containers

    - name: exec
      container:
        image: alpine
        command: [sh, -c]
        args:
          - |
            echo foo (bar)

$ argo get test-x8gk2
Name:                test-x8gk2
Namespace:           argo
ServiceAccount:      basic-workflow
Status:              Running
Created:             Fri Jan 25 08:53:34 -0500 (5 minutes ago)
Started:             Fri Jan 25 08:53:34 -0500 (5 minutes ago)
Duration:            5 minutes 0 seconds
Parameters:          
  items:             [ "1", "2", "3", "4" ]


STEP               PODNAME                DURATION  MESSAGE
 ● test-x8gk2                                       
 └-·-✖ step1(0:1)                                   child 'test-x8gk2-2931933513' failed
   | └---✖ foo     test-x8gk2-2931933513  3s        failed with exit code 2
   ├-✖ step1(1:2)                                   child 'test-x8gk2-3072094959' failed
   | └---✖ foo     test-x8gk2-3072094959  3s        failed with exit code 2
   ├-● step1(2:3)                                   
   | └---✖ foo     test-x8gk2-1920784633  3s        failed with exit code 2
   └-✖ step1(3:4)                                   child 'test-x8gk2-1530984219' failed
     └---✖ foo     test-x8gk2-1530984219  1s        failed with exit code 2

This is for argo 2.2.1, I deployed argo constrained to a namespace using https://github.com/argoproj/argo/tree/master/manifests/namespace-install