Detox build with Expo - "Error: Could not find build script in detox.configurations["ios.sim"].build"

Goal: I would like to be able to run detox tests for an expo app with Travis.

I created a bare-bones expo app that successfully runs a single detox test on my local machine. After pushing to git and running on Travis, all dependencies install successfully and then the Travis build scripts fail with the following error.

Error: Error: Could not find build script in detox.configurations["ios.sim"].build

Issue: It looks like the issue occurs because there isn't a "build" entry in the "ios.sim" configuration for "detox" in package.json. For a non-expo React Native project with detox, the corresponding .xcodeproject or .xxworkspace can be built directly. Expo doesn't have a .xcodeproject or .xcworkspace - what to put for the "build" configuration for an Expo project? While there is an Exponent.the app provided by the expo to run tests with detox, I don't see any .xcodeproject or .xcworkspace to build with.

Repro steps:

• Clone git@github.com:bryanboyko/expo-detox-travis-3.git
• cd expo-detox-travis-3
• npm install
• ./setup.sh
• detox test
• push to a new branch and create a PR to see travis build

Travis failure log: https://travis-ci.com/bryanboyko/expo-detox-travis-3/builds/151879107