by default TektonConfig CR created with "spec.targetNamespace" as openshift-pipelines.
We can change the targetNamespace to different value. By changing the "targetNamespace" deletes the existing namespace "openshift-pipelines" and creates  all the components to the new targetNamespace. However it is not working properly.

steps to reproduce

• index image used to test: registry-proxy.engineering.redhat.com/rh-osbs/iib:583030
• setup TektonConfig CR with defaults
• once all TektonConfig CR comes to "True", update the "spec.targetNamespace" to "openshift-pipelines-alt"

  $ tkn version
  Client version: 0.32.0
  Chains version: v0.17.0
  Pipeline version: v0.50.1
  Triggers version: v0.25.0
  Operator version: v0.68.0
  
  $ oc version
  Client Version: 4.11.0
  Kustomize Version: v4.5.4
  Server Version: 4.13.11
  Kubernetes Version: v1.26.7+0ef5eae
  
  $ oc get ns openshift-pipelines
  Error from server (NotFound): namespaces "openshift-pipelines" not found
  [jkandasa@earth tekton]$ oc get ns openshift-pipelines-alt
  NAME                      STATUS   AGE
  openshift-pipelines-alt   Active   77s
  
  
  $ oc get pods --namespace openshift-pipelines-alt
  NAME                                                READY   STATUS              RESTARTS   AGE
  tekton-chains-controller-7f64499c84-94v9r           0/1     ContainerCreating   0          44s
  tekton-triggers-controller-54bf75b8c9-dx6zx         1/1     Running             0          40s
  tekton-triggers-core-interceptors-9f8cf5b5b-fvf5w   1/1     Running             0          39s
  tekton-triggers-webhook-64695b5464-9bz4k            1/1     Running             0          40s
  
  
  $ oc get tektonconfigs.operator.tekton.dev config
  NAME     VERSION   READY   REASON
  config   1.12.0    False   Components not in ready state: TektonPipeline: reconcile again and proceed
  
  
  $ oc get tektoninstallerset
  NAME                                             READY   REASON
  addon-custom-clustertask-gljxg                   True    
  addon-custom-communityclustertask-w5qm7          True    
  addon-custom-consolecli-kwlmn                    True    
  addon-custom-openshiftconsole-9jzp5              False   Install failed with message: namespaces "openshift-pipelines" not found
  addon-custom-pipelinestemplate-czp89             True    
  addon-custom-triggersresources-6s857             True    
  addon-versioned-clustertasks-1.12-rw2tt          True    
  chain-config-jwv76                               True    
  chain-gx9w2                                      False   Controller: tekton-chains-controller deployment not ready
  openshiftpipelinesascode-main-deployment-hvc4d   False   Install failed with message: namespaces "openshift-pipelines" not found
  openshiftpipelinesascode-main-static-zdffh       False   Install failed with message: namespaces "openshift-pipelines" not found
  openshiftpipelinesascode-post-7jlxx              True    
  pipeline-main-deployment-ljk58                   False   Install failed with message: namespaces "openshift-pipelines" not found
  pipeline-main-static-79sks                       False   Install failed with message: namespaces "openshift-pipelines" not found
  pipeline-post-xz6cm                              True    
  pipeline-pre-rf4jj                               True    
  rhosp-rbac-p24rv                                 True    
  tektoncd-pruner-trrf2                            False   Install failed with message: namespaces "openshift-pipelines" not found
  trigger-main-deployment-vdz85                    True    
  trigger-main-static-tpl9g                        True    
  validating-mutating-webhoook-g89gl               True    
  
  

Workaround:

• delete all the tektonInstallersets manually, new tektonInstallersets will be recreated with updated targetNamespace.