"Error: spawn git ENOENT" when running react-scripts test

I have a project that I created using the create-react-app. When I first created the project the tests ran fine. I decided to run the tests after not running them for a while (I still haven't written any so the generated test class is all I have) and now I'm getting the following error:

Determining test suites to run...Error: spawn git ENOENT
    at Process.ChildProcess._handle.onexit (internal/child_process.js:178:32)
    at onErrorNT (internal/child_process.js:344:16)
    at nextTickCallbackWith2Args (node.js:442:9)
    at process._tickCallback (node.js:356:17)

Git is definitely on the path, I can run git --version from the command line and it outputs as expected. I get the same error if I run in cygwin or the windows command line.

My package.json looks like:

{
  "name": "my-app",
  "version": "0.1.0",
  "private": true,
  "dependencies": {
    "immutable": "^3.8.1",
    "react": "^15.5.4",
    "react-dom": "^15.5.4"
  },
  "devDependencies": {
    "react-scripts": "0.9.5"
  },
  "scripts": {
    "start": "react-scripts start",
    "build": "react-scripts build",
    "test": "react-scripts test --env=jsdom",
    "eject": "react-scripts eject"
  }
}

via Matt Watson