yarn build just hangs when completed

Question

I thought i had figured out what the problem was but alas, i did not. When running my build script yarn build or even npm run build the script builds just fine but the process never completes and just hangs... Does anyone have an idea on how to go about troubleshooting this sort of problem?

here's my package.json

{
  "name": "stars-app",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "axios": "^0.16.2",
    "bulma": "^0.5.1",
    "custom-react-scripts": "0.2.0",
    "firebase": "^4.3.0",
    "font-awesome": "^4.7.0",
    "lodash": "^4.17.4",
    "react": "^15.6.1",
    "react-dom": "^15.6.1",
    "react-feather": "^1.0.7",
    "react-router-dom": "^4.2.2",
    "styled-components": "^2.1.2"
  },
  "scripts": {
    "start": "NODE_PATH=src react-scripts start",
    "build": "NODE_PATH=src react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  },
  "devDependencies": {
    "firebase-tools": "^3.9.2"
  }
}