Revoke Mint authority

Question

I'm trying to revoke the mint authority in my code using Anchor. I've tried many things, but I always get an error during deployment. Whenever I add set_authority to my code, I encounter the following error during deployment:

Error: Deploying program failed: RPC response error -32002: Transaction simulation failed: Error processing Instruction 0: account data too small for instruction [3 log messages] There was a problem deploying: Output { status: ExitStatus(unix_wait_status(256)), stdout: '', stderr: '' }.

When set_authority is not included, the deployment works fine. Does anyone know what might be causing this issue and how to resolve it? pub fn mint_tokens(ctx: Context, quantity: u64) -> Result<()> { let seeds = &["mint".as_bytes(), &[ctx.bumps.mint]]; let signer = [&seeds[..]];

    mint_to(
        CpiContext::new_with_signer(
            ctx.accounts.token_program.to_account_info(),
            MintTo {
                authority: ctx.accounts.mint.to_account_info(),
                to: ctx.accounts.destination.to_account_info(),
                mint: ctx.accounts.mint.to_account_info(),
            },
            &signer,
        ),
        quantity,
    )?;
    set_authority(
        CpiContext::new_with_signer(
            ctx.accounts.token_program.to_account_info(),
            SetAuthority {
                account_or_mint: ctx.accounts.mint.to_account_info(),
                current_authority: ctx.accounts.mint.to_account_info(),
            },
            &signer,
        ),
        spl_token::instruction::AuthorityType::MintTokens,
        None, // Entferne die Mint-Authority
    )?;

    Ok(())
}

//Account:

  #[derive(Accounts)]
    pub struct MintTokens<'info> {
#[account(
    mut,
    seeds = [b"mint"],
    bump,
    mint::authority = mint,
)]
pub mint: Account<'info, Mint>,
#[account(
    init_if_needed,
    payer = payer,
    associated_token::mint = mint,
    associated_token::authority = payer,
)]
pub destination: Account<'info, TokenAccount>,
#[account(mut)]
pub payer: Signer<'info>,
pub rent: Sysvar<'info, Rent>,
pub system_program: Program<'info, System>,
pub token_program: Program<'info, Token>,
pub associated_token_program: Program<'info, AssociatedToken>,

}

Answer 1

I think you need to set authority to null

In Rust you would do this

Some(None)