Google cloud build failure: Service call error

Question

Would like to ask if there is anyone who has encountered this problem with google cloud build:

Service call error. Function: [get], Argument: [path_value {
  segments {
    simple: "databases"
  }
  segments {
    simple: "(default)"
  }
  segments {
    simple: "documents"
  }
  segments {
    simple: "users"
  }
  segments {
    simple: "9g5l9Jz2Sn299hI06e5I62zcVmeL"
  }
  segments {
    simple: "user_restaurants"
  }
  segments {
    simple: "restaurant_1"
  }
}
]. for 'create' @ L228
com.google.cloud.datastore.core.exception.DatastoreException: 
Service call error. Function: [get], Argument: [path_value {
  segments {
    simple: "databases"
  }
  segments {
    simple: "(default)"
  }
  segments {
    simple: "documents"
  }
  segments {
    simple: "users"
  }
  segments {
    simple: "9g5l9Jz2Sn299hI06e5I62zcVmeL"
  }
  segments {
    simple: "user_restaurants"
  }
  segments {
    simple: "restaurant_1"
  }
}
]. for 'create' @ L228
    at com.google.cloud.datastore.core.exception.DatastoreException$Builder.build(DatastoreException.java:111)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRulesAuthorizer.verboseError(EmulatorRulesAuthorizer.java:289)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRulesAuthorizer.withVerboseErrors(EmulatorRulesAuthorizer.java:266)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRulesAuthorizer.checkCommit(EmulatorRulesAuthorizer.java:118)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1.commitHelper(CloudFirestoreV1.java:873)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1.internalCommit(CloudFirestoreV1.java:780)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1.internalCommit(CloudFirestoreV1.java:764)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1.write(CloudFirestoreV1.java:753)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1WriteStream.handleRequest(CloudFirestoreV1WriteStream.java:208)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1WriteStream.write(CloudFirestoreV1WriteStream.java:136)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1WriteStream.onNext(CloudFirestoreV1WriteStream.java:92)
    at com.google.cloud.datastore.emulator.impl.CloudFirestoreV1WriteStream.onNext(CloudFirestoreV1WriteStream.java:25)
    at com.google.cloud.datastore.emulator.firestore.webchannel.FirestoreV1WebChannelAdapter$FirestoreWriteHandler.onMessage(FirestoreV1WebChannelAdapter.java:141)
    at com.google.cloud.datastore.emulator.firestore.webchannel.FirestoreV1WebChannelAdapter$FirestoreWriteHandler.onMessage(FirestoreV1WebChannelAdapter.java:111)
    at com.google.net.webchannel.server.v8.ChannelInternalImpl.onMessage(ChannelInternalImpl.java:485)
    at com.google.net.webchannel.server.v8.ForwardChannel.deliverMessage(ForwardChannel.java:114)
    at com.google.net.webchannel.server.v8.ForwardChannel.processPendingRequest(ForwardChannel.java:93)
    at com.google.net.webchannel.server.v8.ForwardChannel.consume(ForwardChannel.java:67)
    at com.google.net.webchannel.server.v8.ForwardChannel.add(ForwardChannel.java:60)
    at com.google.net.webchannel.server.v8.ChannelInternalImpl.handleRequestParams(ChannelInternalImpl.java:260)
    at com.google.net.webchannel.server.v8.ChannelInternalImpl.processSessionRequest(ChannelInternalImpl.java:317)
    at com.google.net.webchannel.server.v8.ChannelInternalImpl.handle(ChannelInternalImpl.java:142)
    at com.google.net.webchannel.server.v8.ChannelInternalImpl.consume(ChannelInternalImpl.java:78)
    at com.google.net.webchannel.server.common.ChannelProcessor.run(ChannelProcessor.java:80)
Caused by: com.google.firebase.rules.runtime.common.EvaluationException: Error: /workspace/firestore.rules line [35], column [30]. Service call error. Function: [get], Argument: [path_value {
  segments {
    simple: "databases"
  }
  segments {
    simple: "(default)"
  }
  segments {
    simple: "documents"
  }
  segments {
    simple: "users"
  }
  segments {
    simple: "9g5l9Jz2Sn299hI06e5I62zcVmeL"
  }
  segments {
    simple: "user_restaurants"
  }
  segments {
    simple: "restaurant_1"
  }
}
].
    at com.google.firebase.rules.runtime.impl.DefaultEvaluator$TransformEvaluationException.apply(DefaultEvaluator.java:292)
    at com.google.firebase.rules.runtime.impl.DefaultEvaluator$TransformEvaluationException.apply(DefaultEvaluator.java:277)
    at com.google.common.util.concurrent.AbstractCatchingFuture$AsyncCatchingFuture.doFallback(AbstractCatchingFuture.java:204)
    at com.google.common.util.concurrent.AbstractCatchingFuture$AsyncCatchingFuture.doFallback(AbstractCatchingFuture.java:191)
    at com.google.common.util.concurrent.AbstractCatchingFuture.run(AbstractCatchingFuture.java:134)
    at com.google.common.util.concurrent.DirectExecutor.execute(DirectExecutor.java:33)
    at com.google.common.util.concurrent.AbstractFuture.executeListener(AbstractFuture.java:1283)
    at com.google.common.util.concurrent.AbstractFuture.addListener(AbstractFuture.java:764)
    at com.google.common.util.concurrent.FluentFuture$TrustedFuture.addListener(FluentFuture.java:124)
    at com.google.common.util.concurrent.AbstractCatchingFuture.create(AbstractCatchingFuture.java:57)
    at com.google.common.util.concurrent.Futures.catchingAsync(Futures.java:411)
    at com.google.firebase.rules.runtime.impl.DefaultEvaluator.evaluate(DefaultEvaluator.java:193)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRuleClient$EmulatorRuleEvaluator.evaluate(EmulatorRuleClient.java:91)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRuleClient$EmulatorRuleEvaluator.evaluate(EmulatorRuleClient.java:81)
    at com.google.cloud.datastore.core.auth.rules.SinglePhaseRulesAuthorizer.evaluate(SinglePhaseRulesAuthorizer.java:475)
    at com.google.cloud.datastore.core.auth.rules.SinglePhaseRulesAuthorizer.access$200(SinglePhaseRulesAuthorizer.java:80)
    at com.google.cloud.datastore.core.auth.rules.SinglePhaseRulesAuthorizer$CommitAuthorizerImpl.checkAccess(SinglePhaseRulesAuthorizer.java:702)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRulesAuthorizer.lambda$checkCommit$0(EmulatorRulesAuthorizer.java:126)
    at com.google.cloud.datastore.emulator.impl.rules.EmulatorRulesAuthorizer.withVerboseErrors(EmulatorRulesAuthorizer.java:261)
    ... 21 more

I've recently updated our firebase sdk and firebase admin sdk to use the firebase emulator suite and at first our e2e tests are working perfectly, no flakiness at all. Then the only thing I did was merge the recent changes from our master branch to the branch I'm currently working on and it suddenly started failing inconsistently. I've checked the changes I have merged and nothing seems to be a probable reason for this issue. Hope someone can help point out to me why this error is happening.