juju.rpc panic running request

[Mark Beierl]

Attempting to deploy this plan: https://github.com/canonical/charmed-5g/tree/main/examples/terraform/mastering

Failed on the sdcore-nms-k8s operator, and the following is observed in the controller debug-log:

```
controller-0: 15:50:32 CRITICAL juju.rpc panic running request {MethodCaller:0xc007680c90 transformErrors:0x3c616c0 hdr:{RequestId:2 Request:{Type:Application Version:19 Id: Action:DeployFromRepository} Error: ErrorCode: ErrorInfo:map[] Version:1}} with arg {Args:[{CharmName:sdcore-nms-k8s ApplicationName:nms AttachStorage:[] Base:0xc007d401a0 Channel:0xc005070a80 ConfigYAML:nms: {}
 Cons: Devices:map[] DryRun:false EndpointBindings:map[] Force:false NumUnits:0xc0060b4880 Placement:[] Revision:0xc0060b4888 Resources:map[] Storage:map[] Trust:true}]}: runtime error: invalid memory address or nil pointer dereference
goroutine 21330785 [running]:
runtime/debug.Stack()
 /snap/go/current/src/runtime/debug/stack.go:24 +0x65
github.com/juju/juju/rpc.(*Conn).runRequest.func1()
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/rpc/server.go:558 +0x7d
panic({0x6b1d140, 0xc0f1440})
 /snap/go/current/src/runtime/panic.go:884 +0x213
github.com/juju/charm/v12.MetaFormatReasons({0x0, 0x0})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/vendor/github.com/juju/charm/v12/charm.go:75 +0x39
github.com/juju/charm/v12.MetaFormat(...)
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/vendor/github.com/juju/charm/v12/charm.go:103
github.com/juju/juju/core/charm.IsKubernetes({0x0, 0x0})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/core/charm/kubernetes.go:17 +0x3f
github.com/juju/juju/apiserver/facades/client/application.caasDeployFromRepositoryValidator.ValidateArg({_, {_, _}, {_, _}, {_, _}, _}, {{0xc0060b4860, 0xe}, ...})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/apiserver/facades/client/application/deployrepository.go:509 +0x1a7
github.com/juju/juju/apiserver/facades/client/application.(*DeployFromRepositoryAPI).DeployFromRepository(_, {{0xc0060b4860, 0xe}, {0xc0060b4848, 0x3}, {0x0, 0x0, 0x0}, 0xc007d401a0, 0xc005070a80, ...})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/apiserver/facades/client/application/deployrepository.go:91 +0x175
github.com/juju/juju/apiserver/facades/client/application.(*APIBase).DeployFromRepository(0xc00640a700, {{0xc00050a500?, 0x4?, 0x0?}})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/apiserver/facades/client/application/application.go:3060 +0x195
reflect.Value.call({0x76e6a40?, 0xc0085899d0?, 0x40f447?}, {0x78a7820, 0x4}, {0xc006420b88, 0x1, 0xafae25?})
 /snap/go/current/src/reflect/value.go:586 +0xb07
reflect.Value.Call({0x76e6a40?, 0xc0085899d0?, 0x6d1c840?}, {0xc006420b88?, 0x0?, 0x40f06a?})
 /snap/go/current/src/reflect/value.go:370 +0xbc
github.com/juju/rpcreflect.newMethod.func8({0x8413db8, 0xc009514cd0}, {0x76e6a40?, 0xc0085899d0?, 0x6debb20?}, {0x6d1c840?, 0xc00607ed80?, 0x5cc256?})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/vendor/github.com/juju/rpcreflect/type.go:365 +0xce
github.com/juju/juju/apiserver.(*srvCaller).Call(0xc007680c90, {0x8413db8, 0xc009514cd0}, {0x0?, 0x1?}, {0x6d1c840?, 0xc00607ed80?, 0x0?})
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/apiserver/root.go:205 +0xa6
github.com/juju/juju/rpc.(*Conn).runRequest(0xc0033897c0, {{0x83fa5a0, 0xc007680c90}, 0x7b813a0, {0x2, {{0xc0060b4830, 0xb}, 0x13, {0x0, 0x0}, ...}, ...}}, ...)
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/rpc/server.go:571 +0x1b6
created by github.com/juju/juju/rpc.(*Conn).handleRequest
 /build/snapcraft-juju-5c4e26ef528b8affefabcd9eccf0889b/parts/jujud/build/rpc/server.go:475 +0x685
```

[Mark Beierl (mbeierl)]

juju --version
3.4.2-genericlinux-amd64

[Mark Beierl (mbeierl)]

Bart on our team discovered this happens when the Terraform plan references a track that does not yet have a release.

ref: https://matrix.to/#/!DYZQXnMeycataPvFYj:ubuntu.com/$zA-RQdsv0-B6gHwnEQ3KYL-NwBRFun-XzMR8ChjIFOM?via=ubuntu.com&via=matrix.org&via=mozilla.org

[Harry Pidcock (hpidcock)]

Thank-you for the bug report.

[Heather Lanigan (hmlanigan)]

From Mark:

At the time, the TF plan referenced sdcore-nms-k8s in 1.4/edge, but that track doesn’t exist. So really any plan that references an invalid track

[Heather Lanigan (hmlanigan)]

https://github.com/juju/juju/pull/17188