Merge request approval rule `any_approver` fails during apply if present in GitLab project

Created by: petrmvala

GitLab Provider version

3.12.0

GitLab version

Gitlab 14.8 Edition Ultimate

Terraform version

1.1

Relevant Terraform Configuration

resource "gitlab_project_approval_rule" "codeowners" {
  count = local.gitlab_protect_count == 1 && local.try_codeowners_file ? 1 : 0

  project            = var.gitlab_project
  name               = "Any approver"
  rule_type          = "any_approver"
  approvals_required = 1
}

Relevant log output

│ Error: POST https://gitlab.i-am-not-telling-you.com/api/v4/projects/some-id/approval_rules: 400 {message: {name: [has already been taken]}, {rule_type: [any-approver for the project already exists]}}
│ 
│   with module.my_project.gitlab_project_approval_rule.codeowners[0],
│   on gcp_project/gitlab_protect.tf line 55, in resource "gitlab_project_approval_rule" "codeowners":
│   55: resource "gitlab_project_approval_rule" "codeowners" {

Description

The any_approver approval rule can be present only once in the GitLab project. From UI it gets created automatically when someone increases the number of approvers from 0 to a different number. Even when decreased back to 0, the rule still exists and is not deleted. The rule can only be deleted via API. The Terraform plan does not detect the presence of this rule and therefore produces a valid plan which then fails to apply because API rejects the creation of a new rule.