Rust-Bitcoin Sign Segwit Transaction

I'm trying to sign a segwit transaction in rust-bitcoin. To start with, my transaction setup looks as follows:

let previous_output = OutPoint::new(Txid::from_hex("991ab2b13f6bc6c13002d79d5e9775626a5e7328e14cd16837d50d1cc637dc6a").unwrap(), 0);
let tx_input = TxIn { previous_output, script_sig: Default::default(), sequence: 0xffffffff, witness: Default::default()
};
let tx_output = TxOut { value: 4999995000, script_pubkey: output_details.script_pubkey() // don't worry about this
};
let mut transaction = Transaction { version: 2, lock_time: 0, input: vec![tx_input], output: vec![tx_output]
};

In order to sign the transaction (using Schnorr, by the way), I extract the sighash as follows:

let signature_hash = transaction.signature_hash(0, &output_details.script_pubkey(), 0); // is that really the most idiomatic way of passing a sighash flag in rust-bitcoin?
let message = Message::from_slice(&signature_hash.to_vec()).unwrap();

When I print the hex-serialized message, I get the following value: fa42b9b0f54972b31712b2efbc86db1bf78aa833bc9c969ea7860ef38a25fbaf.

However, in order to sign a segwit transaction, the previous output's amount must also be committed to, and I'm not seeing a way to do that. As far as I can tell, the sighash I should be signing is in fact 61746ec9baa14bbe82586c7f149926b1492871c67dc7fe21e7cfe2f2260a1405.

Finally, though less relevantly, if things were to work fine, here's how my signature process would conlude:

let signature = private_key.sign_schnorr(message);
let signature_vec = signature.as_ref().to_vec();
transaction.input[0].witness = Witness::from_vec(vec![signature_vec]);

Thanks in advance for helping me figure this out!

You can get bonuses upto $100 FREE BONUS when you:
💰 Install these recommended apps:
💲 SocialGood - 100% Crypto Back on Everyday Shopping
💲 xPortal - The DeFi For The Next Billion
💲 CryptoTab Browser - Lightweight, fast, and ready to mine!
💰 Register on these recommended exchanges:
🟡 Binance🟡 Bitfinex🟡 Bitmart🟡 Bittrex🟡 Bitget
🟡 CoinEx🟡 Crypto.com🟡 Gate.io🟡 Huobi🟡 Kucoin.