How to fix Angular6 “_getAriaLabel is not a function” with production build

Problem:

You are building an Angular6 application and in development mode everything works fine. However, if you build in production mode:

ng build --prod --aot

you see an error like this in the client:

main.4d1baabffbba5677af03.js:1 ERROR TypeError: i.ɵnov(...)._getAriaLabel is not a function
    at Object.updateRenderer (main.4d1baabffbba5677af03.js:1)
    at Object.updateRenderer (main.4d1baabffbba5677af03.js:1)
[...]

Solution:

The issue appears to be caused by incorrectly updated NodeJS modules. You can fix it by simply deleting your node_modules folder:

rm -rf node_modules

Furthermore, it’s recommended to update @angular/cli as the bug does not seem to be present in newer versions of @angular/cli:

sudo npm i -g @angular/cli

Source & discussion on GitHub