Problems modifying stale_if_error

[rickardkarlsson]

Terraform Version

Terraform v1.7.4
on darwin_arm64
+ provider registry.terraform.io/datadog/datadog v3.36.1
+ provider registry.terraform.io/fastly/fastly v5.6.0
+ provider registry.terraform.io/hashicorp/google v4.84.0
+ provider registry.terraform.io/hashicorp/google-beta v4.84.0
+ provider registry.terraform.io/hashicorp/random v3.6.0

Affected Fastly Terraform Resource(s)

Please list the affected resources, for example:

• fastly_service_vcl

Terraform Configuration Files

resource "fastly_service_vcl" "this" {
  name = "test.examples.com"
  domain {
    name = "test.examples.com"
  }
  activate       = true
  stale_if_error = true
}

Expected Behavior

When first creating vcl service with:
stale_if_error = true
and change it to(and run apply):
stale_if_error = false
I would like the change to be applied to my fastly service

Actual Behavior

After changing it to stale_if_error = false and run terraform apply it outputs:

  ~ resource "fastly_service_vcl" "this" {
      ~ active_version     = 2 -> (known after apply)
      ~ cloned_version     = 2 -> (known after apply)
        id                 = "xxxxxx"
        name               = "test.examples.com"
      ~ stale_if_error     = true -> false
}

Plan: 0 to add, 1 to change, 0 to destroy.

But change is not applied to the service itself. I have to manually change it in the GUI to apply it

Debug Output (optional)

I can see the following in debug output

2024-02-26T15:17:58.697+0100 [WARN]  Provider "provider[\"registry.terraform.io/fastly/fastly\"]" produced an unexpected new value for fastly_service_vcl.this, but we are tolerating it because it is using the legacy plugin SDK.
    The following problems may be the cause of any confusing errors from downstream operations:
      - .stale_if_error: was cty.False, but now cty.True

Steps to Reproduce

Please list the steps required to reproduce the issue, for example:

1. terraform apply with stale_if_error = true
2. Change stale_if_error = false
3. terraform apply

[Integralist]

Thanks @rickardkarlsson for opening this issue. I've opened an internal ticket to track this and we'll update this GitHub issue when we have any feedback.