TxnLockNotFound

#[tokio::main]
async fn main() -> Result<()> {
    let txn_client = TransactionClient::new(vec!["127.0.0.1:2379"]).await?;
    let mut txn = txn_client.begin_optimistic().await.unwrap();
    let key = "aa".to_owned();
    txn.insert(key.clone(), "value".to_owned()).await.unwrap();
    txn.delete(key.clone()).await.unwrap();
    txn.commit().await.unwrap();
    Ok(())
}

The above code raise the following error:

thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: StringError("KeyError { locked: None, retryable: \"Error(Txn(Error(Mvcc(Error(TxnLockNotFound { start_ts: TimeStamp(427084398190919681), commit_ts: TimeStamp(427084398190919682), key: [97, 97] })))))\", abort: \"\", conflict: None, already_exist: None, deadlock: None, commit_ts_expired: None, txn_not_found: None, commit_ts_too_large: None }")', src/main.rs:347:24
stack backtrace:
   0: rust_begin_unwind
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/std/src/panicking.rs:517:5
   1: core::panicking::panic_fmt
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/core/src/panicking.rs:93:14
   2: core::result::unwrap_failed
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/core/src/result.rs:1617:5
   3: core::result::Result<T,E>::unwrap
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/core/src/result.rs:1299:23
   4: scratch::main::{{closure}}
             at ./src/main.rs:347:5
   5: <core::future::from_generator::GenFuture<T> as core::future::future::Future>::poll
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/core/src/future/mod.rs:80:19
   6: tokio::park::thread::CachedParkThread::block_on::{{closure}}
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/park/thread.rs:263:54
   7: tokio::coop::with_budget::{{closure}}
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/coop.rs:106:9
   8: std::thread::local::LocalKey<T>::try_with
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/std/src/thread/local.rs:399:16
   9: std::thread::local::LocalKey<T>::with
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/std/src/thread/local.rs:375:9
  10: tokio::coop::with_budget
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/coop.rs:99:5
  11: tokio::coop::budget
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/coop.rs:76:5
  12: tokio::park::thread::CachedParkThread::block_on
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/park/thread.rs:263:31
  13: tokio::runtime::enter::Enter::block_on
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/runtime/enter.rs:151:13
  14: tokio::runtime::thread_pool::ThreadPool::block_on
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/runtime/thread_pool/mod.rs:71:9
  15: tokio::runtime::Runtime::block_on
             at /Users/feichao/.cargo/registry/src/github.com-1ecc6299db9ec823/tokio-1.10.0/src/runtime/mod.rs:452:43
  16: scratch::main
             at ./src/main.rs:348:5
  17: core::ops::function::FnOnce::call_once
             at /rustc/ae90dcf0207c57c3034f00b07048d63f8b2363c8/library/core/src/ops/function.rs:227:5

Tikv setup:

Start with the Rust reproduction using TransactionClient, begin_optimistic, insert, delete, and commit, focusing on the failing call at src/main.rs:347. Reproduce the TxnLockNotFound error against the described TiKV setup, then trace the transaction commit path to determine why the inserted-and-deleted key loses its lock. Done means this sequence commits successfully or reports a clearly handled result.