Downloading http://cdn-fastly.deb.debian.org/debian/dists/stretch/InRelease...
Error downloading http://cdn-fastly.deb.debian.org/debian/dists/stretch/InRelease: HTTP code 404 while fetching http://cdn-fastly.deb.debian.org/debian/dists/stretch/InRelease retrying...
Retrying 0 http://cdn-fastly.deb.debian.org/debian/dists/stretch/InRelease...
Giving up on http://cdn-fastly.deb.debian.org/debian/dists/stretch/InRelease...
Downloading http://cdn-fastly.deb.debian.org/debian/dists/stretch/Release...
Success downloading http://cdn-fastly.deb.debian.org/debian/dists/stretch/Release
Downloading http://cdn-fastly.deb.debian.org/debian/dists/stretch/Release.gpg...
Success downloading http://cdn-fastly.deb.debian.org/debian/dists/stretch/Release.gpg

gpgv:  RSA key ID B7D453EC

gpgv:  RSA key ID 22F3D138

gpgv:  RSA key ID 386FA1D9

gpgv:  RSA key ID 1A7B6500

ERROR: unable to fetch mirror: verification of detached signature failed: exit status 2