Delete or Create key fails: Attempting to mutate more than 1 global secondary index at the same time

Describe the bug

When attempting to delete a single key (no other changes) I get:

Attempting to mutate more than 1 global secondary index at the same time on the FooTable table in the Foo stack. 
An error occurred during the push operation: Attempting to mutate more than 1 global secondary index at the same time on the FooTable table in the Foo stack. 

Amplify CLI Version

4.29.2

To Reproduce

1. Have a schema that has already been pushed with an example @key
2. Try to delete the @key
3. amplify push fails

Expected behavior

@key should be deleted

Additional context

Example schema:

type Foo
  @model
  @key(name: "FooStatusUpdatedAt", fields: ["status", "updatedAt"], queryField: "fooStatusUpdatedAt")
  @searchable
{
  updatedAt: AWSDateTime,
  status: PublicationStatus,
  ...
}

enum PublicationStatus {
  draft
}

Note: I downgraded to @aws-amplify/cli@4.27.3 and was able to perform the amplify push without issue.

[malcomm]

Any updates on this?

[dsypniewski]

I have the same problem, and I just found out that the order of the @key directives seems to matter. Going from this:

type Foo
  @model
  @key(name: "FooSubjectId", fields: ["fooSubjectId"], queryField: "fooSubjectId")

to this:

type Foo
  @model
  @key(name: "FooByUpdatedAt", fields: ["searchIndex", "updatedAt"], queryField: "fooByUpdatedAt")
  @key(name: "FooSubjectId", fields: ["fooSubjectId"], queryField: "fooSubjectId")

results in abovementioned error, but instead doing:

type Foo
  @model
  @key(name: "FooSubjectId", fields: ["fooSubjectId"], queryField: "fooSubjectId")
  @key(name: "FooByUpdatedAt", fields: ["searchIndex", "updatedAt"], queryField: "fooByUpdatedAt")

seems to work. My guess is that the diffing in the first case creates something like this:

DELETE FooSubjectId
CREATE FooByUpdatedAt
CREATE FooSubjectId

instead of this:

CREATE FooByUpdatedAt