Multiple Go-tests fail. E.g. RouterBGPVRF, RouterStaticVRFIPv4Unicast and RouterStaticIPv4Unicast

[shebang42]

RP/0/RP0/CPU0:ios#sh ver
Tue Nov  5 13:12:59.482 UTC
Cisco IOS XR Software, Version 7.9.2

> go version
go version go1.23.2 darwin/arm64

When testing #266 , the tests as described in #237 (comment) now fail. Even without these new commits.
Furthermore, the tests for RouterStaticIPv4Unicast (without the VRF) also fail. They all fail with element(s) not found: 'prefix'.

In the meantime, we have downgraded IOS-XR in our lab to 7.9.2, (possibly from 7.11.1) so it might be an incompatibility issue with this version. But my development laptop has changed as well.

Test RouterStaticVRFIPv4Unicast

terraform-provider-iosxr git:(main) IOSXR_USERNAME=cisco IOSXR_PASSWORD=cisco IOSXR_HOST=10.131.3.122:57777 TF_ACC=true go test -v -failfast -fullpath ./... -run RouterStaticVRFIPv4Unicast
?       github.com/CiscoDevNet/terraform-provider-iosxr [no test files]
?       github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider/client        [no test files]
?       github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider/helpers       [no test files]
=== RUN   TestAccDataSourceIosxrRouterStaticVRFIPv4Unicast
--- PASS: TestAccDataSourceIosxrRouterStaticVRFIPv4Unicast (4.03s)
=== RUN   TestAccIosxrRouterStaticVRFIPv4Unicast
    /Users/paul/src/cisco_orig/terraform-provider-iosxr/internal/provider/resource_iosxr_router_static_vrf_ipv4_unicast_test.go:88: Step 1/3 error: Error running post-apply refresh plan: exit status 1
        
        Error: Client Error
        
          with iosxr_router_static_vrf_ipv4_unicast.test,
          on terraform_plugin_test.tf line 11, in resource "iosxr_router_static_vrf_ipv4_unicast" "test":
          11: resource "iosxr_router_static_vrf_ipv4_unicast" "test" {
        
        Get request failed, got error: rpc error: code = NotFound desc = Requested
        element(s) not found: 'prefix'
--- FAIL: TestAccIosxrRouterStaticVRFIPv4Unicast (18.44s)
FAIL
FAIL    github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider       23.150s
FAIL

Test RouterStaticIPv4Unicast (without VRF)

(nkp) ➜  terraform-provider-iosxr git:(dependabot/github_actions/crazy-max/ghaction-import-gpg-6.2.0) IOSXR_USERNAME=cisco IOSXR_PASSWORD=i[...] IOSXR_HOST=[...] TF_ACC=true go test -v -failfast -fullpath ./... -run RouterStaticIPv4Unicast
        
<...>
          with iosxr_router_static_ipv4_unicast.test,
          on terraform_plugin_test.tf line 11, in resource "iosxr_router_static_ipv4_unicast" "test":
          11: resource "iosxr_router_static_ipv4_unicast" "test" {
        
        Get request failed, got error: rpc error: code = NotFound desc = Requested
        element(s) not found: 'prefix'
--- FAIL: TestAccIosxrRouterStaticIPv4Unicast (16.28s)
FAIL
FAIL    github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider       21.012s
FAIL

I encounter the same error when testing on an old (v0.3.2 / Commit: 372a870) version:

terraform-provider-iosxr git:(372a870) ✗ IOSXR_USERNAME=cisco IOSXR_PASSWORD=[...] IOSXR_HOST=[...] TF_ACC=true go test -v -failfast -fullpath ./... -run RouterStaticIPv4Unicast
<...>
        element(s) not found: 'prefix'

Test RouterBGPVRF

Also the test from #246 (comment) fails on the current main branch.

terraform-provider-iosxr git:(main) IOSXR_USERNAME=cisco IOSXR_PASSWORD=cisco IOSXR_HOST=10.131.3.122:57777 TF_ACC=true go test -v -failfast -fullpath ./... -run RouterBGPVRF
?       github.com/CiscoDevNet/terraform-provider-iosxr [no test files]
?       github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider/client        [no test files]
?       github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider/helpers       [no test files]
=== RUN   TestAccDataSourceIosxrRouterBGPVRFAddressFamily
--- PASS: TestAccDataSourceIosxrRouterBGPVRFAddressFamily (12.31s)
=== RUN   TestAccDataSourceIosxrRouterBGPVRFNeighborAddressFamily
    /Users/paul/src/cisco_orig/terraform-provider-iosxr/internal/provider/data_source_iosxr_router_bgp_vrf_neighbor_address_family_test.go:38: Step 1/1 error: Error running apply: exit status 1
        
        Error: Client Error
        
          with iosxr_router_bgp_vrf_neighbor_address_family.test,
          on terraform_plugin_test.tf line 76, in resource "iosxr_router_bgp_vrf_neighbor_address_family" "test":
          76: resource "iosxr_router_bgp_vrf_neighbor_address_family" "test" {
        
        Set request failed, got error: rpc error: code = Internal desc = {
         "cisco-grpc:errors": {
          "error": [
           {
            "error-type": "application",
            "error-tag": "operation-failed",
            "error-severity": "error",
            "error-path": "Cisco-IOS-XR-um-router-bgp-cfg:router/bgp/as[as-number = '65001']/vrfs/vrf[vrf-name = 'VRF1']/neighbors/neighbor[neighbor-address = '10.1.1.2']/address-families/address-family[af-name = 'ipv4-unicast']/next-hop-self",
            "error-message": "'sysdb' detected the 'warning' condition 'A verifier or EDM callback function returned: 'not found''"
           }
          ]
         }
        }
        
--- FAIL: TestAccDataSourceIosxrRouterBGPVRFNeighborAddressFamily (24.35s)
FAIL
FAIL    github.com/CiscoDevNet/terraform-provider-iosxr/internal/provider       37.337s
FAIL