Comment 13 for bug 1530548

WARNING: Signed boot verification is disabled; enabling it for security.
You can disable it again using: sudo crossystem dev_boot_signed_only=0
Installing xenial-armhf chroot to /usr/local/chroots/xenial
Downloading latest debootstrap...
Download from Debian gitweb failed. Trying latest release...
2017-06-01 22:17:29 URL:http://cdn-fastly.deb.debian.org/debian/pool/main/d/debootstrap/ [7115/7115] -> "-" [1]
Downloading debootstrap version 1.0.90...
2017-06-01 22:17:29 URL:http://cdn-fastly.deb.debian.org/debian/pool/main/d/debootstrap/debootstrap_1.0.90.tar.gz [69936/69936] -> "-" [1]
Patching debootstrap...
Downloading bootstrap files...
W: Cannot check Release signature; keyring file not available /usr/share/keyrings/ubuntu-archive-keyring.gpg