[2778] Error while running command "npm run test" or "yarn run test"

I'm trying to work on improvements to nuxt.js, but when cloning the repository, installing its dependencies and running tests without changes, there is always an error or process stop.

• git: 2.16.0.windows.2
• node: 9.4.0
• npm: 5.6.0

git clone https://github.com/nuxt/nuxt.js.git
cd nuxt.js
npm install // yarn install

// Error
npm run test // yarn run test

// OK
npm run test-appveyor // yarn run test-appveyor