I reinstalled the latest xenial packages: ii apt 1.2.15 amd64 commandline package manager ii apt-transport-https 1.2.15 amd64 https download transport for APT ii libapt-inst2.0:amd64 1.2.15 amd64 deb package format runtime library ii libapt-pkg-perl 0.1.29build7 amd64 Perl interface to libapt-pkg ii libapt-pkg5.0:amd64 1.2.15 amd64 package management runtime library and now apt-get update is unhappy again: sarnold@hunt:/mnt/ubuntu/.zfs/snapshot/rsync.30/pool/main/a/apt$ sudo apt-get update Hit:1 http://mirrors.kernel.org/ubuntu xenial InRelease Hit:2 http://security.debian.org jessie/updates InRelease Hit:3 http://security.debian.org wheezy/updates InRelease Hit:4 http://mirrors.kernel.org/ubuntu xenial-updates InRelease Hit:5 http://mirrors.kernel.org/ubuntu xenial-security InRelease Ign:6 http://mirrors.kernel.org/ubuntu precise InRelease Hit:7 http://mirrors.kernel.org/ubuntu precise-updates InRelease Err:1 http://mirrors.kernel.org/ubuntu xenial InRelease At least one invalid signature was encountered. Hit:8 http://mirrors.kernel.org/ubuntu precise-security InRelease Hit:9 http://mirrors.kernel.org/ubuntu precise-proposed InRelease Ign:10 http://mirrors.kernel.org/ubuntu trusty InRelease Err:2 http://security.debian.org jessie/updates InRelease At least one invalid signature was encountered. Hit:11 http://mirrors.kernel.org/ubuntu trusty-updates InRelease Hit:12 http://mirrors.kernel.org/ubuntu trusty-security InRelease Err:3 http://security.debian.org wheezy/updates InRelease At least one invalid signature was encountered. Hit:13 http://mirrors.kernel.org/ubuntu trusty-proposed InRelease Hit:14 http://mirrors.kernel.org/ubuntu xenial-proposed InRelease Hit:15 http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu vivid InRelease Ign:16 http://archive.canonical.com/ubuntu precise InRelease Get:17 http://security.ubuntu.com/ubuntu xenial-security InRelease [94.5 kB] Err:4 http://mirrors.kernel.org/ubuntu xenial-updates InRelease At least one invalid signature was encountered. Hit:18 http://mirrors.kernel.org/ubuntu yakkety InRelease Hit:19 http://ftp.debian.org/debian unstable InRelease Hit:20 http://mirrors.kernel.org/ubuntu yakkety-updates InRelease Hit:21 http://mirrors.kernel.org/ubuntu yakkety-security InRelease Err:5 http://mirrors.kernel.org/ubuntu xenial-security InRelease At least one invalid signature was encountered. Hit:22 http://mirrors.kernel.org/ubuntu yakkety-proposed InRelease Hit:23 http://mirrors.kernel.org/ubuntu zesty InRelease Err:7 http://mirrors.kernel.org/ubuntu precise-updates InRelease At least one invalid signature was encountered. Hit:24 http://mirrors.kernel.org/ubuntu zesty-updates InRelease Ign:25 http://archive.canonical.com/ubuntu trusty InRelease Hit:26 http://ppa.launchpad.net/snappy-dev/image/ubuntu vivid InRelease Hit:27 http://mirrors.kernel.org/ubuntu zesty-security InRelease Hit:28 http://ftp.debian.org/debian testing InRelease Err:8 http://mirrors.kernel.org/ubuntu precise-security InRelease At least one invalid signature was encountered. Hit:29 http://mirrors.kernel.org/ubuntu zesty-proposed InRelease Hit:30 http://mirrors.kernel.org/ubuntu precise Release Err:9 http://mirrors.kernel.org/ubuntu precise-proposed InRelease At least one invalid signature was encountered. Hit:31 http://mirrors.kernel.org/ubuntu trusty Release Err:11 http://mirrors.kernel.org/ubuntu trusty-updates InRelease At least one invalid signature was encountered. Hit:32 http://archive.canonical.com/ubuntu xenial InRelease Hit:33 http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu xenial InRelease Ign:34 http://ftp.debian.org/debian jessie InRelease Err:12 http://mirrors.kernel.org/ubuntu trusty-security InRelease At least one invalid signature was encountered. Err:13 http://mirrors.kernel.org/ubuntu trusty-proposed InRelease At least one invalid signature was encountered. Hit:35 http://archive.canonical.com/ubuntu yakkety InRelease Err:14 http://mirrors.kernel.org/ubuntu xenial-proposed InRelease At least one invalid signature was encountered. Hit:36 http://ftp.debian.org/debian jessie-updates InRelease Err:15 http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu vivid InRelease At least one invalid signature was encountered. Err:18 http://mirrors.kernel.org/ubuntu yakkety InRelease At least one invalid signature was encountered. Hit:37 http://archive.canonical.com/ubuntu zesty InRelease Err:19 http://ftp.debian.org/debian unstable InRelease At least one invalid signature was encountered. Ign:38 http://ftp.debian.org/debian wheezy InRelease Err:20 http://mirrors.kernel.org/ubuntu yakkety-updates InRelease At least one invalid signature was encountered. Err:21 http://mirrors.kernel.org/ubuntu yakkety-security InRelease At least one invalid signature was encountered. Hit:39 http://archive.canonical.com/ubuntu precise Release Err:22 http://mirrors.kernel.org/ubuntu yakkety-proposed InRelease At least one invalid signature was encountered. Hit:40 http://ftp.debian.org/debian wheezy-updates InRelease Err:23 http://mirrors.kernel.org/ubuntu zesty InRelease At least one invalid signature was encountered. Hit:41 http://archive.canonical.com/ubuntu trusty Release Err:24 http://mirrors.kernel.org/ubuntu zesty-updates InRelease At least one invalid signature was encountered. Err:26 http://ppa.launchpad.net/snappy-dev/image/ubuntu vivid InRelease At least one invalid signature was encountered. Hit:42 http://ftp.debian.org/debian jessie Release Err:27 http://mirrors.kernel.org/ubuntu zesty-security InRelease At least one invalid signature was encountered. Err:28 http://ftp.debian.org/debian testing InRelease At least one invalid signature was encountered. Err:29 http://mirrors.kernel.org/ubuntu zesty-proposed InRelease At least one invalid signature was encountered. Hit:43 http://ftp.debian.org/debian wheezy Release Err:44 http://mirrors.kernel.org/ubuntu precise Release.gpg At least one invalid signature was encountered. Err:45 http://mirrors.kernel.org/ubuntu trusty Release.gpg At least one invalid signature was encountered. Err:32 http://archive.canonical.com/ubuntu xenial InRelease At least one invalid signature was encountered. Err:33 http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu xenial InRelease At least one invalid signature was encountered. Err:17 http://security.ubuntu.com/ubuntu xenial-security InRelease At least one invalid signature was encountered. Err:35 http://archive.canonical.com/ubuntu yakkety InRelease At least one invalid signature was encountered. Err:36 http://ftp.debian.org/debian jessie-updates InRelease At least one invalid signature was encountered. Err:37 http://archive.canonical.com/ubuntu zesty InRelease At least one invalid signature was encountered. Err:46 http://archive.canonical.com/ubuntu precise Release.gpg At least one invalid signature was encountered. Err:40 http://ftp.debian.org/debian wheezy-updates InRelease At least one invalid signature was encountered. Err:47 http://archive.canonical.com/ubuntu trusty Release.gpg At least one invalid signature was encountered. Err:48 http://ftp.debian.org/debian jessie Release.gpg At least one invalid signature was encountered. Err:49 http://ftp.debian.org/debian wheezy Release.gpg At least one invalid signature was encountered. Fetched 94.5 kB in 2s (47.0 kB/s) Reading package lists... Done W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu xenial InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://security.debian.org jessie/updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://security.debian.org wheezy/updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu xenial-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu xenial-security InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu precise-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu precise-security InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu precise-proposed InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu trusty-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu trusty-security InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu trusty-proposed InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu xenial-proposed InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu vivid InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu yakkety InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ftp.debian.org/debian unstable InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu yakkety-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu yakkety-security InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu yakkety-proposed InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu zesty InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu zesty-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ppa.launchpad.net/snappy-dev/image/ubuntu vivid InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu zesty-security InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ftp.debian.org/debian testing InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu zesty-proposed InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu precise Release: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://mirrors.kernel.org/ubuntu trusty Release: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com/ubuntu xenial InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu xenial InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://security.ubuntu.com/ubuntu xenial-security InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com/ubuntu yakkety InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ftp.debian.org/debian jessie-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com/ubuntu zesty InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com/ubuntu precise Release: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ftp.debian.org/debian wheezy-updates InRelease: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://archive.canonical.com/ubuntu trusty Release: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ftp.debian.org/debian jessie Release: At least one invalid signature was encountered. W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: http://ftp.debian.org/debian wheezy Release: At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/xenial/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/xenial-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/xenial-security/InRelease At least one invalid signature was encountered. W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/xenial-security/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu/dists/vivid/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ppa.launchpad.net/snappy-dev/image/ubuntu/dists/vivid/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ppa.launchpad.net/ci-train-ppa-service/stable-phone-overlay/ubuntu/dists/xenial/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/precise-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/precise-security/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/precise-proposed/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/trusty-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/trusty-security/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/trusty-proposed/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/xenial-proposed/InRelease At least one invalid signature was encountered. W: Failed to fetch http://archive.canonical.com/ubuntu/dists/xenial/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/yakkety/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/yakkety-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/yakkety-security/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/yakkety-proposed/InRelease At least one invalid signature was encountered. W: Failed to fetch http://archive.canonical.com/ubuntu/dists/yakkety/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/zesty/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/zesty-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/zesty-security/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/zesty-proposed/InRelease At least one invalid signature was encountered. W: Failed to fetch http://archive.canonical.com/ubuntu/dists/zesty/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ftp.debian.org/debian/dists/unstable/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ftp.debian.org/debian/dists/testing/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ftp.debian.org/debian/dists/jessie-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://security.debian.org/dists/jessie/updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://ftp.debian.org/debian/dists/wheezy-updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://security.debian.org/dists/wheezy/updates/InRelease At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/precise/Release.gpg At least one invalid signature was encountered. W: Failed to fetch http://mirrors.kernel.org/ubuntu/dists/trusty/Release.gpg At least one invalid signature was encountered. W: Failed to fetch http://archive.canonical.com/ubuntu/dists/precise/Release.gpg At least one invalid signature was encountered. W: Failed to fetch http://archive.canonical.com/ubuntu/dists/trusty/Release.gpg At least one invalid signature was encountered. W: Failed to fetch http://ftp.debian.org/debian/dists/jessie/Release.gpg At least one invalid signature was encountered. W: Failed to fetch http://ftp.debian.org/debian/dists/wheezy/Release.gpg At least one invalid signature was encountered. W: Some index files failed to download. They have been ignored, or old ones used instead. The *InRelease* files look fine: sarnold@hunt:/var/lib/apt/lists$ for f in *InRelease* ; do apt-key verify $f ; done gpgv: Signature made Wed 09 Nov 2016 05:30:58 AM PST using DSA key ID 437D05B5 gpgv: Good signature from "Ubuntu Archive Automatic Signing Key