npx hardhat compile never runs the optimizer.

[vessenes]

Version of Hardhat

2.20.1

What happened?

solc run with optimizer turned on from the command line compiles my contract to 9k. Without the optimizer, solc compiles to 25k. Regardless of settings, hardhat compiles to 26k.

I can ignore warnings during the development cycle, but this makes testing and deployment impossible.

Minimal reproduction steps

$ npx hardhat compile

Warning: Contract code size is 26036 bytes and exceeds 24576 bytes (a limit introduced in Spurious Dragon). This contract may not be deployable on Mainnet. Consider enabling the optimizer (with a low "runs" value!), turning off revert strings, or using libraries.
  --> contracts/Rewards.sol:12:1:
   |
12 | contract Rewards {
   | ^ (Relevant source part starts here and spans across multiple lines).

$  solc --optimize --combined-json bin Rewards.sol | jq '.contracts["Rewards.sol:Rewards"].bin' | wc -c | awk '{print ($1 - 3) / 2}'

--> Rewards.sol

9210

$ solc --combined-json bin Rewards.sol | jq '.contracts["Rewards.sol:Rewards"].bin' | wc -c | awk '{print ($1 - 3) / 2}' 

--> Rewards.sol

Warning: Contract code size is 25299 bytes and exceeds 24576 bytes (a limit introduced in Spurious Dragon). This contract may not be deployable on Mainnet. Consider enabling the optimizer (with a low "runs" value!), turning off revert strings, or using libraries.
  --> Rewards.sol:12:1:
   |
12 | contract Rewards {
   | ^ (Relevant source part starts here and spans across multiple lines).

25393

my config:

$ cat hardhat.config.ts 
import { HardhatUserConfig } from "hardhat/config";
import "@nomicfoundation/hardhat-toolbox";

const config: HardhatUserConfig = {
  solidity: "0.8.23",
   optimizer: {
        enabled: true,
        runs: 10,
      },
  solidity: "0.8.24",
   optimizer: {
        enabled: true,
        runs: 10,
      },
};

export default config;

Search terms

compile optimizer size solidity

[vessenes]

... And is if by magic, github was my rubber duck.

For reference, hardhat will not complain about malformed solidity settings. Here is a proper, working config:

import { HardhatUserConfig } from "hardhat/config";
import "@nomicfoundation/hardhat-toolbox";

const config: HardhatUserConfig = {
    solidity: {
        version: "0.8.23",
        settings: {
            optimizer: {
                enabled: true,
                runs: 10,
            },
        },
    },
};

export default config;

note the solidity object, and the settings object inlined, both different from my original.