user126793: What's "bitcoin-util grind" for?
  grind
       Perform proof of work on hex header string


user208: It performs proof-of-work mining; given a block header, it finds a nonce such that the header with the nonce in it hashes to a value below the proof-of-work target.
Its purpose is assisting with signet creation. In signet, blocks have a small amount of proof-of-work (they're relatively low difficulty), but also require a signature by the (fixed) signers for the network. In order to assist these signers in their block-creation process, the grind command of bitcoin-util can be invoked.
To be clear, this feature is not useful for normal mainnet or even testnet mining:

It is CPU only, unable to take advantage of specific hardware like GPUs, FPGAs, or ASICs.
Even for a CPU-only mining tool, it is slow. It lacks optimizations that could speed it up, in order to improve maintainability and simplicity of the code.
It has no interface to interact with mining protocols like Stratum or GBT.


126793: <p>What's &quot;bitcoin-util grind&quot; for?</p>
<pre><code>  grind
       Perform proof of work on hex header string
</code></pre>
 208: <p>It performs proof-of-work mining; given a block header, it finds a nonce such that the header with the nonce in it hashes to a value below the proof-of-work target.</p>
<p>Its purpose is assisting with signet creation. In signet, blocks have a small amount of proof-of-work (they're relatively low difficulty), but also require a signature by the (fixed) signers for the network. In order to assist these signers in their block-creation process, the <code>grind</code> command of <code>bitcoin-util</code> can be invoked.</p>
<p>To be clear, this feature is not useful for normal mainnet or even testnet mining:</p>
<ul>
<li>It is CPU only, unable to take advantage of specific hardware like GPUs, FPGAs, or ASICs.</li>
<li>Even for a CPU-only mining tool, it is slow. It lacks optimizations that could speed it up, in order to improve maintainability and simplicity of the code.</li>
<li>It has no interface to interact with mining protocols like Stratum or GBT.</li>
</ul>
