Error with ng --build

[fulv]

@ebrehault When I ran ng build --prod I got this error:

Module not found: Error: Can't resolve './$$_gendir/app/app.module.ngfactory'

Doing ng build --env=prod instead, fixed it for me.

I didn't do any of the version upgrades recommended in https://stackoverflow.com/questions/42718095/module-not-found-error-cant-resolve-gendir-app-app-module-ngfactory, though they might be a good idea.

I have "@angular/cli": "1.2.3", for what it's worth.