Another compilation issue reported as a bug

It looks like you may have hit a bugin graphql-schema-linter.

It would be super helpful if you could report this here: https://github.com/cjoudrey/graphql-schema-linter/issues/new

Error: Expected Interface type.
    at invariant (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/jsutils/invariant.js:19:11)
    at produceInterfaceType (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/utilities/buildASTSchema.js:260:83)
    at /usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/utilities/buildASTSchema.js:334:14
    at Array.map (native)
    at makeImplementedInterfaces (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/utilities/buildASTSchema.js:333:45)
    at interfaces (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/utilities/buildASTSchema.js:312:16)
    at resolveThunk (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/type/definition.js:169:40)
    at defineInterfaces (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/type/definition.js:331:20)
    at GraphQLObjectType.getInterfaces (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/type/definition.js:315:52)
    at typeMapReducer (/usr/src/app/node_modules/graphql-schema-linter/node_modules/graphql/type/schema.js:205:23)

# test.schema

schema {
  viewer: Viewer
}

type Person {
  email: String
}

# Error triggered because of this.
type Viewer implements Person {
  email: String
}

[mscharley]

No problem! Just reporting things as I run into them. In my case the Person type has moved back and forth between an interface and a type a few times while we design the schema and I forgot that we last settled on a type.

[cjoudrey]

Will be fixed in next release by #163.