[EASY] Improve settlement tx cancellation logging (#3165)

# Description
ATM, it is not possible to understand whether a settlement cancellation
tx succeeded. This PR adds logs with the cancellation tx hash, so it
will be possible to check the transaction on chain later. Also,
additional context is added when working with the cancellation tx
submission since, currently, it is impossible to distinguish between the
actual settlement tx submission error.

crates/driver/src/domain/mempools.rs

@@ -4,9 +4,14 @@ use {
         eth,
     },
     crate::{
-        domain::{competition::solution::Settlement, eth::TxStatus, BlockNo},
+        domain::{
+            competition::solution::Settlement,
+            eth::{TxId, TxStatus},
+            BlockNo,
+        },
         infra::{self, observe, solver::Solver, Ethereum},
     },
+    anyhow::Context,
     ethrpc::block_stream::into_stream,
     futures::{future::select_ok, FutureExt, StreamExt},
     thiserror::Error,
@@ -123,24 +128,32 @@ impl Mempools {
                     TxStatus::Pending => {
                         // Check if the current block reached the submission deadline block number
                         if block.number >= submission_deadline {
+                            let cancellation_tx_hash = self
+                                .cancel(mempool, settlement.gas.price, solver)
+                                .await
+                                .context("cancellation tx due to deadline failed")?;
                             tracing::info!(
-                                ?hash,
+                                settle_tx_hash = ?hash,
                                 deadline = submission_deadline,
                                 current_block = block.number,
+                                ?cancellation_tx_hash,
                                 "tx not confirmed in time, cancelling",
                             );
-                            self.cancel(mempool, settlement.gas.price, solver).await?;
                             return Err(Error::Expired);
                         }
                         // Check if transaction still simulates
                         if let Err(err) = self.ethereum.estimate_gas(tx).await {
                             if err.is_revert() {
+                                let cancellation_tx_hash = self
+                                    .cancel(mempool, settlement.gas.price, solver)
+                                    .await
+                                    .context("cancellation tx due to revert failed")?;
                                 tracing::info!(
-                                    ?hash,
+                                    settle_tx_hash = ?hash,
+                                    ?cancellation_tx_hash,
                                     ?err,
                                     "tx started failing in mempool, cancelling"
                                 );
-                                self.cancel(mempool, settlement.gas.price, solver).await?;
                                 return Err(Error::SimulationRevert);
                             } else {
                                 tracing::warn!(?hash, ?err, "couldn't re-simulate tx");
@@ -173,7 +186,7 @@ impl Mempools {
         mempool: &infra::mempool::Mempool,
         pending: eth::GasPrice,
         solver: &Solver,
-    ) -> Result<(), Error> {
+    ) -> Result<TxId, Error> {
         let cancellation = eth::Tx {
             from: solver.address(),
             to: solver.address(),
@@ -186,8 +199,7 @@ impl Mempools {
             limit: CANCELLATION_GAS_AMOUNT.into(),
             price: pending * GAS_PRICE_BUMP,
         };
-        mempool.submit(cancellation, gas, solver).await?;
-        Ok(())
+        mempool.submit(cancellation, gas, solver).await
     }
 }