Using arrays parameters in Matrix

[sambonbonne]

Hello,

I'm trying to use matrix with the kaniko task which takes an EXTRA_ARGS parameter (an array of string).

So here is my pipeline task:

    - name: build
      runAfter: ["clone"]
      taskRef:
        name: kaniko
      workspaces:
        - name: source
          workspace: source-code
      params:
        - name: DOCKERFILE
          value: "Containerfile"
      matrix:
        params:
          - name: EXTRA_ARGS
            value:
              - ["--no-push", "--target production", "--build-arg MY_VAR=toto"]

I expect to get a generated YAML like:

    - name: build
      runAfter: ["clone"]
      taskRef:
        name: kaniko
      workspaces:
        - name: source
          workspace: source-code
      params:
        - name: DOCKERFILE
          value: "Containerfile"
        - name: EXTRA_ARGS
          value: ["--no-push", "--target", "production", "--build-arg", "MY_VAR=toto"]

But I guess it does not work because I get the following error with tkn logs <pipelinerun-name>:

parameters of type array only are allowed, but param EXTRA_ARGS has type string

Did I do something wrong when trying to use an array of arrays in matrix.params.[].value?

Thanks for any help!