operator-sdk generate bundle fails with Kubebuilder v4-generated PROJECT file: unknown field “cliVersion”

[rayowang]

Description:

I encountered this issue while drafting documentation titled “Distributing Projects Built with Kubebuilder with Steps”. Although I managed to work around it temporarily by manually editing the PROJECT file, I believe this is not an ideal or sustainable solution. Therefore, I’m filing this issue in the hope that it can get more attention and possibly lead to a more robust fix or guidance.

Here’s what happened in detail: I used the latest version of Kubebuilder (v4.0+, specifically with cliVersion: 4.6.0) to scaffold a new operator project. The generated PROJECT file looks like this:

# Code generated by tool. DO NOT EDIT.
# This file is used to track the info used to scaffold your project
# and allow the plugins properly work.
# More info: https://book.kubebuilder.io/reference/project-config.html
cliVersion: 4.6.0
domain: mydomain.com
layout:
- go.kubebuilder.io/v4
projectName: kubebuilderdemo1
repo: github.com/myorg/my-operator
resources:
- api:
    crdVersion: v1
    namespaced: true
  controller: true
  domain: mydomain.com
  group: app
  kind: MyApp
  path: github.com/myorg/my-operator/api/v1
  version: v1
version: "3"

However, when I try to generate the bundle using operator-sdk, it fails with the following error:

  --version 0.1.0 \
  --kustomize-dir config/manifests \
  --output-dir ./bundle \
  --package my-operator \
  --channels alpha \
  --default-channel alpha

Error output:

Error: unable to load the configuration: unable to unmarshal config at "PROJECT": 
error unmarshalling project configuration: error unmarshaling JSON: 
while decoding JSON: json: unknown field "cliVersion"

Expected behavior:

The operator-sdk generate bundle command should be able to parse the PROJECT file generated by the latest Kubebuilder without errors.

Environment:

•	Kubebuilder version: 4.6.0
•	Operator SDK version: v1.40.0
•	Go version: go1.24.x
•	OS: macOS (Apple Silicon)

Possible Cause:

It seems operator-sdk doesn’t yet support the new cliVersion field or layout: go.kubebuilder.io/v4 introduced by Kubebuilder v4.

Suggested Fix:

Ensure that operator-sdk can recognize and parse Kubebuilder v4 project configs, or provide clear guidance on compatibility (e.g., whether operator-sdk is expected to support v4 layouts).

[camilamacedo86]

Hi @rayowang 👋

Thanks for raising this!

Indeed, the cliVersion field was introduced in Kubebuilder v4.6.0, but the operator-sdk has not yet been updated to recognize this new field. This is tracked in this work-in-progress PR. The issue should be resolved once the SDK is updated to support Kubebuilder >= v4.6.0.

Just to clarify, this is not a bug in Kubebuilder, but rather a compatibility gap between the latest Kubebuilder-generated project structure and the current version of Operator SDK.

Note: Since this field is new and optional, it might be missing in some setups. Also, the cliVersion field is part of the PROJECT configuration file, which is used internally by the plugin system.

As a workaround, we might want to just remove the field from the PROJECT file before running the command to generate the bundle but I would suggest you keep the value after that in the PROJECT file since it will allow you take advantage of the new feature that we have been working on to keep the projects updated which will be a game change for users see: #4302

Closing this one. But feel free to re-open if you see that fit.