# Upgrading guppy basecaller on Oxford Nanopore Gridion via PPA

I am trying to update the guppy_basecaller (current version installed is 3.2.10+aabd4ec) on a ONT Gridion device. I am initially trying to update it via the nanopore PPA, as described here (requires login access to the nanopore community)

After I issued sudo apt update, I got a GPG error, saying that the public key was not found in the system.

W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://europe.oxfordnanoportal.com/apt xenial-stable InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AD9D09AF2EBBA5A8
W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: https://mirror.oxfordnanoportal.com/apt xenial-stable-gridion InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AD9D09AF2EBBA5A8
W: Failed to fetch https://mirror.oxfordnanoportal.com/apt/dists/xenial-stable-gridion/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AD9D09AF2EBBA5A8
W: Failed to fetch http://mirror.oxfordnanoportal.com/apt/dists/xenial-stable/InRelease  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY AD9D09AF2EBBA5A8



I came across a possible solution shown here, so I tried to add the key to the system with the following command:

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys AD9D09AF2EBBA5A8


The terminal was busy for too long and, after some time I got an timeout error:

Executing: /tmp/tmp.EWnOg4cPJk/gpg.1.sh --keyserver
keyserver.ubuntu.com
--recv-keys
gpg: requesting key 2EBBA5A8 from hkp server keyserver.ubuntu.com
gpg: keyserver timed out
gpg: keyserver receive failed: keyserver error


I then came across this post where one potential solution was to change the port, so I issued:

sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys AD9D09AF2EBBA5A8


But then I got:

Executing: /tmp/tmp.sfqFuJpVb2/gpg.1.sh --keyserver
hkp://keyserver.ubuntu.com:80
--recv-keys
gpg: requesting key 2EBBA5A8 from hkp server keyserver.ubuntu.com
gpg: no valid OpenPGP data found.
gpg: Total number processed: 0
gpg: keyserver communications error: bad public key


Has anyone managed to update the guppy_basecaller via PPA, as described in the nanopore community page?

An alternative would be to install via the .tar.gz file, though I am first trying to upgrade the current version from the PPA to avoid conflicts with the current installation.

sudo apt-get update
export PLATFORM=$$(lsb_release -cs) ### wget -O- https://mirror.oxfordnanoportal.com/apt/ont-repo.pub | sudo apt-key add - ### echo "deb http://mirror.oxfordnanoportal.com/apt$${PLATFORM}-stable non-free" | sudo tee /etc/apt/sources.list.d/nanoporetech.sources.list

• Yes it turned out that the upgrade worked after repeating all these commands (which I thought it was not necessary because I had already added the PPA). There was, however, an issue with the release, so export PLATFORM=\$(lsb_release -cs) fixed the issue Feb 25 at 14:28