Sapphire.randomBytes returns zeros on HardHat about sapphire-paratime

[nhynes]

This is a problem with all of the precompiles, though. The upcoming hardhat precompiles will fix the problem when sapphire-hardhat is used, though not otherwise, but then that's just due to not following the instructions. I'd say for now we should wait for the hardhat precompiles. If you want, you could add a function like

function isSapphire() external view returns (bool) {
    return block.chainid == 0x5aff || block.chainid == 0x5afe;
}

and then call that in your contract's constructor

[nhynes]

Thanks for the report. A precondition of Sapphire.sol is that it's used in a Sapphire-like environment, so it's not a goal of this library to check that it's being called correctly. Do you know of a way to emit a compile-time error if it's not being used correctly? I would accept a change that avoids adding gas cost to each invocation.

[CedarMist]

I don't think there's any way to perform a check at compile-time.

I ran into this same problem when first starting with Sapphire, and have seen it encountered again on Discord.

The gas cost of additional checks is minimal, instead of the existing "require()" with error message, both status & length check could be combined into a check, with a more generic per-function error?

if ( false == success || entropy.length != numBytes ) revert Precompile_RandomBytes_Error();