user134069: I have precisely followed the instructions for attempting to verify the latest 23.0 release of bitcoind on Linux, available here: https://bitcoincore.org/en/download/
I have gpg imported all the keys defined here:
https://raw.githubusercontent.com/bitcoin/bitcoin/master/contrib/builder-keys/keys.txt
I have then ran gpg --verify SHA256SUMS.asc SHA256SUMS and when I do this, gpg is reporting multiple keys are not certified with a trusted signature - there is no indication that the signature belongs to the owner - providing an exit status code of 2.
My script therefor does not proceed to download and unpack the latest bitcoind binary.
I don't believe I am doing anything wrong and I suspect this is a key hygiene issue that the devs need to get on top of. Is anyone else experiencing this issue, and if not, can provide some insight into a fix?
Thank you.
UPDATE
There are also several can't check signature: no public key errors on the gpg verification output so this is probably the main cause of the problem.

user48884: 
I have then ran gpg --verify SHA256SUMS.asc SHA256SUMS and when I do this, gpg is reporting multiple keys are not certified with a trusted signature - there is no indication that the signature belongs to the owner - providing an exit status code of 2.

This error is a result of how GPG determines whether it trusts keys. When a key is signed by another key, the signer indicates that they have verified that the key belongs to the person it claims is its owner. This property is transitive, to a degree (that is configured by you, locally). So if GPG sees a key signed by a key that you trust, then it will also indicate that you trust that key, even if you yourself have not signed it. You can also indicate (locally) to GPG that you trust a key, and with what level you trust it.
This particular error message means that the GPG does not see anything that indicates that it trusts those keys. It may mean that you have not signed someone's key who has signed those keys. It may be that your GPG simply does not have anything in its trust database and so it defaults to not trusting any key (this is the likely scenario for most users).
This security.SE question goes into further detail.

134069: <p>I have precisely followed the instructions for attempting to verify the latest 23.0 release of <code>bitcoind</code> on Linux, available here: <a href="https://bitcoincore.org/en/download/" rel="nofollow noreferrer">https://bitcoincore.org/en/download/</a></p>
<p>I have gpg imported all the keys defined here:</p>
<p><a href="https://raw.githubusercontent.com/bitcoin/bitcoin/master/contrib/builder-keys/keys.txt" rel="nofollow noreferrer">https://raw.githubusercontent.com/bitcoin/bitcoin/master/contrib/builder-keys/keys.txt</a></p>
<p>I have then ran <code>gpg --verify SHA256SUMS.asc SHA256SUMS</code> and when I do this, gpg is reporting multiple keys are <code>not certified with a trusted signature - there is no indication that the signature belongs to the owner</code> - providing an exit status code of 2.</p>
<p>My script therefor does not proceed to download and unpack the latest <code>bitcoind</code> binary.</p>
<p>I don't believe I am doing anything wrong and I suspect this is a key hygiene issue that the devs need to get on top of. Is anyone else experiencing this issue, and if not, can provide some insight into a fix?</p>
<p>Thank you.</p>
<p><strong>UPDATE</strong></p>
<p>There are also several <code>can't check signature: no public key</code> errors on the gpg verification output so this is probably the main cause of the problem.</p>
 48884: <blockquote>
<p>I have then ran <code>gpg --verify SHA256SUMS.asc SHA256SUMS</code> and when I do this, gpg is reporting multiple keys are <code>not certified with a trusted signature - there is no indication that the signature belongs to the owner</code> - providing an exit status code of 2.</p>
</blockquote>
<p>This error is a result of how GPG determines whether it trusts keys. When a key is signed by another key, the signer indicates that they have verified that the key belongs to the person it claims is its owner. This property is transitive, to a degree (that is configured by you, locally). So if GPG sees a key signed by a key that you trust, then it will also indicate that you trust that key, even if you yourself have not signed it. You can also indicate (locally) to GPG that you trust a key, and with what level you trust it.</p>
<p>This particular error message means that the GPG does not see anything that indicates that it trusts those keys. It may mean that you have not signed someone's key who has signed those keys. It may be that your GPG simply does not have anything in its trust database and so it defaults to not trusting any key (this is the likely scenario for most users).</p>
<p>This <a href="https://security.stackexchange.com/q/147447">security.SE question</a> goes into further detail.</p>
