Hi, Evan

I'm confused, this issue related to the CRD?

Yes,

The CRD lacks the proper schema, which means that invalid data can make it to the operator.

The latest payload is 4.2.0-0.nightly-2019-08-26-235330, but the OLM version is 414ead11612825cabf3fb44323b7018af04ada14 which this fixed PR hasn't been merged in.
mac:~ jianzhang$ oc exec catalog-operator-6b55979bdc-d9d2q -- olm --version
OLM version: 0.11.0
git commit: 414ead11612825cabf3fb44323b7018af04ada14

Change status to MODIFIED first.

OLM version:
mac:~ jianzhang$ oc exec catalog-operator-5b7798599-jpkzb -- olm --version
OLM version: 0.11.0
git commit: 21160c27bcc7ecb34a7babf33d010c557e0f075f

Cluster version is 4.2.0-0.nightly-2019-08-28-004049

1, Create an OperatorGroup resource in the default project.
mac:~ jianzhang$ cat og.yaml 
apiVersion: operators.coreos.com/v1
kind: OperatorGroup
metadata:
  name: test-og
  namespace: default
spec:
  targetNamespaces:
  - default
mac:~ jianzhang$ oc create -f og.yaml 
operatorgroup.operators.coreos.com/test-og created

2, Try to create the subscription with the config field, get the errors below.

mac:~ jianzhang$ oc create -f sub-etcd-42-config.yaml 
The Subscription "etcd-config-test" is invalid: []: Invalid value: map[string]interface {}{"apiVersion":"operators.coreos.com/v1alpha1", "kind":"Subscription", "metadata":map[string]interface {}{"creationTimestamp":"2019-08-28T06:53:52Z", "generation":1, "name":"etcd-config-test", "namespace":"default", "uid":"98a322d9-c960-11e9-9c68-0210964a06ba"}, "spec":map[string]interface {}{"channel":"singlenamespace-alpha", "config":[]interface {}{map[string]interface {}{"env":[]interface {}{map[string]interface {}{"name":"PROXY_HTTP", "value":"test"}}}}, "installPlanApproval":"Automatic", "name":"etcd", "source":"community-operators", "sourceNamespace":"openshift-marketplace", "startingCSV":"etcdoperator.v0.9.4"}}: validation failure list:
spec.config in body must be of type object: "array"

mac:~ jianzhang$ oc get sub
No resources found.

mac:~ jianzhang$ cat sub-etcd-42-config.yaml 
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: etcd-config-test
  namespace: default
spec:
  config:
  - env:
    - name: PROXY_HTTP
      value: test
  channel: singlenamespace-alpha
  installPlanApproval: Automatic
  name: etcd
  source: community-operators
  sourceNamespace: openshift-marketplace
  startingCSV: etcdoperator.v0.9.4


3, Create a subscription without the `config` field.
mac:~ jianzhang$ cat sub-etcd-42.yaml 
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
  name: etcd-config-test
  namespace: default
spec:
  channel: singlenamespace-alpha
  installPlanApproval: Automatic
  name: etcd
  source: community-operators
  sourceNamespace: openshift-marketplace
  startingCSV: etcdoperator.v0.9.4

mac:~ jianzhang$ oc create -f sub-etcd-42.yaml 
subscription.operators.coreos.com/etcd-config-test created

mac:~ jianzhang$ oc get sub
NAME               PACKAGE   SOURCE                CHANNEL
etcd-config-test   etcd      community-operators   singlenamespace-alpha
mac:~ jianzhang$ oc get csv
NAME                  DISPLAY   VERSION   REPLACES              PHASE
etcdoperator.v0.9.4   etcd      0.9.4     etcdoperator.v0.9.2   Succeeded
mac:~ jianzhang$ oc get pods
NAME                             READY   STATUS    RESTARTS   AGE
etcd-operator-7dcf8b48c9-7vkfb   3/3     Running   0          72s

LGTM, verify it first.

One more question, I followed this https://github.com/operator-framework/operator-lifecycle-manager/blob/master/Documentation/contributors/design-proposals/operator-config.md#subscription-spec-changes to set the "config" field, but still get the above error.
So, what's the correct format for the `config` field? The JSON format of the above YAML as below, I guess this `config` field is an array.
Correct me if I'm wrong.

format 1:
{ apiVersion: 'operators.coreos.com/v1alpha1',
  kind: 'Subscription',
  metadata: { name: 'etcd-config-test', namespace: 'default' },
  spec: 
   { config: [ { env: [ { name: 'PROXY_HTTP', value: 'test' } ] } ],
     channel: 'singlenamespace-alpha',
     installPlanApproval: 'Automatic',
     name: 'etcd',
     source: 'community-operators',
     sourceNamespace: 'openshift-marketplace',
     startingCSV: 'etcdoperator.v0.9.4' } }

format 2:
{ apiVersion: 'operators.coreos.com/v1alpha1',
  kind: 'Subscription',
  metadata: { name: 'etcd-config-test', namespace: 'default' },
  spec: 
   { config: [ { env: null, test: [ { name: 'PROXY_HTTP', value: 'test' } ] } ],
     channel: 'singlenamespace-alpha',
     installPlanApproval: 'Automatic',
     name: 'etcd',
     source: 'community-operators',
     sourceNamespace: 'openshift-marketplace',
     startingCSV: 'etcdoperator.v0.9.4' } }

Both failed.

- 'config' is not an array.
- 'env' is an array of object with 'name' and 'value'
 
apiVersion: operators.coreos.com/v1alpha1
kind: Subscription
metadata:
name: etcd
namespace: local
spec:
  channel: singlenamespace-alpha
  name: etcd
  source: operatorhubio-catalog
  sourceNamespace: local
  config:
    env:
    - name: MY_ENV1
      value: "my_env1_value"
    - name: MY_ENV2
      value: "my_env2_value"
    - name: NO_PROXY
      value: "foo,bar"

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2019:2922