Angular 9 - NGCC fails with an unhandled exception

Question

Buidling the application after having upgraded dependcies to Angular 9 (and having performed necessary code changes) throws an error:

Compiling @ang

Answer 1

I had to go into my tsconfig.spec.json file and add

"angularCompilerOptions": {
    "enableIvy": false
}

It was already in my tsconfig.json file.