I have inadvertently deleted the key that allows for updating of the system, and now when I try updating I get the following message

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Fatal error: W: An error occurred during the signature verification. The repository is not updated and the previous index files will be used. GPG error: file:/var/lib/preinstalled-pool focal Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E5231016A6508C17
E: file:/var/lib/preinstalled-pool focal Release.gpg is not (yet) available (The following signatures couldn't be verified because the public key is not available: NO_PUBKEY E5231016A6508C17)

How do I reinstall the public key, given that the error message says it is unavailable? FWIW I have an additional laptop with the same KDE Neon installed. so perhaps I could copy the key from this?

This command might solve your issue:

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sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17

PS - You might have to change the keyserver to whatever PPA you were using for this to work.

dbergstein wrote:This command might solve your issue:

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sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17

PS - You might have to change the keyserver to whatever PPA you were using for this to work.

I have already tried this approach, with various iterations of available keyservers I could find in other forums, but I still get the same error

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sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17
Executing: /tmp/apt-key-gpghome.9C4VgNK1PH/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17
gpg: keyserver receive failed: No data

The problem seems to be that the key is unavailable. As to the PPA suggestion, I have not installed any additional PPAs, so perhaps there is one installed by default that I'm unaware of? If so, how do I check this?

Dekalog wrote:

dbergstein wrote:This command might solve your issue:

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sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17

PS - You might have to change the keyserver to whatever PPA you were using for this to work.

I have already tried this approach, with various iterations of available keyservers I could find in other forums, but I still get the same error

Code: Select all

sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17
Executing: /tmp/apt-key-gpghome.9C4VgNK1PH/gpg.1.sh --keyserver keyserver.ubuntu.com --recv-key E5231016A6508C17
gpg: keyserver receive failed: No data

The problem seems to be that the key is unavailable. As to the PPA suggestion, I have not installed any additional PPAs, so perhaps there is one installed by default that I'm unaware of? If so, how do I check this?

Perhaps exporting the key in question from your other kde installation would be the best approach. This can be done on the other box with the following command:

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apt-key export E5231016A6508C17 > key-data

Transfer this key to the original kde machine and import it:

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sudo apt-key add key-data

Where key-data is an arbitrary file name for the key data you need to transfer. Hope this helps!

dbergstein wrote:Perhaps exporting the key in question from your other kde installation would be the best approach. This can be done on the other box with the following command:

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apt-key export E5231016A6508C17 > key-data

Transfer this key to the original kde machine and import it:

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sudo apt-key add key-data

Where key-data is an arbitrary file name for the key data you need to transfer. Hope this helps!

This appears to have solved the problem. Many thanks.