"invalid schnorr signature" Taproot script usage included

I am trying to sweep funds from an address generated with the following descriptor:

tr(ff13a3311d3e14239bcbb9dfd5d304f4b57c32c0b35d313cb5255f93d7b2dc68,and_v(v:pk(b064bd37b71b7c39355f866e022287097757b05bb1790ecffc5de5fbf07cff69),sha256(a02e93b3dce9cb6031055905d94b04516819ef8fdae4c498777350469e6352dd)))#pygtzret

I set up funds for a local registration test using nigiri I am using to test this situation rust-bitcoin Build a transaction. As far as I know, I’m building the input witness correctly. However, if you check the output transactions using: testmempoolacceptI continually get mandatory-script-verify-flag-failed (Invalid Schnorr signature). It looks like the key you are using is correct. I saw a comment below this answer suggesting that’s my signature serialization, even though I’m using the default. However, using what I think we currently have, bitcoin::taproot::Signature It doesn’t solve my problem.

I’m sure I’m doing something subtly wrong here. So any nudge in the right direction would be greatly appreciated. My entire program is below.

use std::str::FromStr;

use anyhow::{Result, anyhow, bail};
use bitcoin::absolute::LockTime;
use bitcoin::consensus::Encodable;
use bitcoin::hashes::{Hash, sha256};
use bitcoin::hex::prelude::*;
use bitcoin::key::Keypair;
use bitcoin::secp256k1::{Message, Secp256k1};
use bitcoin::sighash::{Prevouts, SighashCache};
use bitcoin::transaction::Version;
use bitcoin::{
    Address, Amount, Network, OutPoint, TapSighashType, Transaction, TxIn, TxOut, Witness,
    XOnlyPublicKey, taproot,
};
use miniscript::Descriptor;

const DESCRIPTOR: &str = "tr(ff13a3311d3e14239bcbb9dfd5d304f4b57c32c0b35d313cb5255f93d7b2dc68,and_v(v:pk(b064bd37b71b7c39355f866e022287097757b05bb1790ecffc5de5fbf07cff69),sha256(a02e93b3dce9cb6031055905d94b04516819ef8fdae4c498777350469e6352dd)))#pygtzret";
const PREIMAGE: &str = "366d2eff102fd290e7be0226f3dd746f4657bce85f08eeef55d0a7777d1a313f";
const PRIVATE_KEY: &str = "0301e0480b374b32851a9462db29dc19fe830a7f7d7a88b81612b9d42099c0ae";

fn main() -> Result<()> {
    let Descriptor::Tr(taproot) = Descriptor::::from_str(DESCRIPTOR)? else {
        bail!("not a taproot descriptor");
    };
    assert_eq!(
        taproot.address(Network::Regtest).to_string(),
        "bcrt1prg82xfnv265zvl0mt6q2rr39mpmskrf2nyum4hqnmdwen3kzsn3slts4sh"
    );
    let total = Amount::from_str("0.0025 BTC")?;
    let previous_output =
        OutPoint::from_str("44afabb1b631d2cd265910dc6befef7e3962df486ad4a4a12f83668c58c9c22c:0")?;
    let txin = TxIn {
        previous_output,
        ..Default::default()
    };

    let to_address = Address::from_str("bcrt1q9th3z6mknxp60avl9xq8vac05q4xgvygx7r7jz")?
        .require_network(Network::Regtest)?;
    let txout = TxOut {
        value: Amount::ZERO,
        script_pubkey: to_address.script_pubkey(),
    };

    let outputs = vec!(txout);
    let mut tx = Transaction {
        version: Version::TWO,
        lock_time: LockTime::ZERO,
        input: vec!(txin),
        output: outputs.clone(),
    };
    // Basic 5 sats/vbyte fee
    let fee = Amount::from_sat(tx.vsize() as u64 * 5);
    tx.output(0).value = total - fee;

    let preimage: (u8; 32) = FromHex::from_hex(PREIMAGE)?;
    let preimage_hash = sha256::Hash::hash(&preimage);
    assert!(
        preimage_hash.to_string()
            == "a02e93b3dce9cb6031055905d94b04516819ef8fdae4c498777350469e6352dd"
    );

    let secp = Secp256k1::new();
    let keypair = Keypair::from_seckey_str(&secp, PRIVATE_KEY)?;
    let public_key = XOnlyPublicKey::from(keypair.public_key());
    assert_eq!(
        public_key.to_string(),
        "b064bd37b71b7c39355f866e022287097757b05bb1790ecffc5de5fbf07cff69"
    );

    let spend_info = taproot.spend_info();
    let leaf = spend_info
        .leaves()
        .next()
        .ok_or(anyhow!("taptree leaf missing"))?;

    let mut sighash_cache = SighashCache::new(&tx);
    let prevouts = Prevouts::All(&outputs);
    let sighash = sighash_cache.taproot_script_spend_signature_hash(
        0,
        &prevouts,
        leaf.leaf_hash(),
        TapSighashType::Default,
    )?;
    let message = Message::from_digest(*sighash.as_ref());
    let signature = taproot::Signature {
        signature: secp.sign_schnorr(&message, &keypair),
        sighash_type: TapSighashType::Default,
    };

    let mut witness = Witness::new();
    witness.push(preimage);
    witness.push(signature.serialize());
    witness.push(leaf.script());
    witness.push(leaf.into_control_block().serialize());
    tx.input(0).witness = witness;

    let mut bytes = Vec::new();
    tx.consensus_encode(&mut bytes)?;
    println!("{}", bytes.to_lower_hex_string());

    Ok(())
}