Websocket upgrade error messages are discarded

[nightkr]

Current and expected behavior

For the following code, that tries to attach to a pod running in the cluster:

        let pods = Api::<Pod>::namespaced(..);
        let mut attachment = pods
            .attach(
                ..,
                &AttachParams::default()
                    .container(debug_container_name)
                    .stdout(true),
            )
            .await
            .context(AttachSnafu)?;

We return a... less than helpful error message about upgrading the websocket:

An unrecoverable error occured: debug command error

Caused by these errors (recent errors listed first):
 1: Attach
 2: failed to upgrade to a WebSocket connection
 3: failed to switch protocol

After digging into the request, the server's response actually contains the following much more helpful error:

rpc error: code = InvalidArgument desc = tty and stderr cannot both be true

Possible solution

UpgradeConnectionError::ProtocolSwitch should also contain (and report) the response body.

Additional context

This is from a slightly old version of kube, but looking through the changelogs I don't see a mention of this changing since.

Environment

Client Version: v1.28.4
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.27.3

Configuration and features

k8s-openapi v0.20.0
├── kube v0.87.1 (/home/n/Documents/stackable/stackable-admin/vendor/kube)
├── kube-client v0.87.1 (/home/n/Documents/stackable/stackable-admin/vendor/kube-client)
│   ├── kube v0.87.1 (/home/n/Documents/stackable/stackable-admin/vendor/kube) (*)
│   └── kube-runtime v0.87.1
│       └── kube v0.87.1 (/home/n/Documents/stackable/stackable-admin/vendor/kube) (*)
├── kube-core v0.87.1
│   ├── kube v0.87.1 (/home/n/Documents/stackable/stackable-admin/vendor/kube) (*)
│   └── kube-client v0.87.1 (/home/n/Documents/stackable/stackable-admin/vendor/kube-client) (*)
├── kube-runtime v0.87.1 (*)

Affected crates

kube-client

Would you like to work on fixing this bug?

None