Doctrine annotation not existing

[matthew]

@kfeldt

W: GPG error: http://dl.google.com/linux/chrome/deb stable Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 78BD65473CB3BD13
E: The repository ‘http://dl.google.com/linux/chrome/deb stable Release’ is not signed.
N: Updating from such a repository can’t be done securely, and is therefore disabled by default.

That error is completely unrelated to Composer; it looks like an error from apt-get, as it is referencing a debian repository.

Packages for PHP are installed using Composer. Can you verify that you were running composer update, composer install, or composer require?