Add a proper error type to ContinuallyRan

This isn't necessary. Because we just log the error, we never match off of it,
we don't need any structure beyond String (or now Debug, which still gives us
a way to print the error). This is for the ergonomics of not having to
constantly write `.map_err(|e| format!("{e:?}"))`.

processor/signers/src/batch/mod.rs

@@ -14,7 +14,7 @@ use serai_db::{Get, DbTxn, Db};
 
 use messages::sign::VariantSignId;
 
-use primitives::task::ContinuallyRan;
+use primitives::task::{DoesNotError, ContinuallyRan};
 use scanner::{BatchesToSign, AcknowledgedBatches};
 
 use frost_attempt_manager::*;
@@ -79,7 +79,9 @@ impl<D: Db, E: GroupEncoding> BatchSignerTask<D, E> {
 }
 
 impl<D: Db, E: Send + GroupEncoding> ContinuallyRan for BatchSignerTask<D, E> {
-  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
+  type Error = DoesNotError;
+
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, Self::Error>> {
     async move {
       let mut iterated = false;
 

processor/signers/src/coordinator/mod.rs

@@ -22,7 +22,9 @@ impl<D: Db, C: Coordinator> CoordinatorTask<D, C> {
 }
 
 impl<D: Db, C: Coordinator> ContinuallyRan for CoordinatorTask<D, C> {
-  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
+  type Error = String;
+
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, Self::Error>> {
     async move {
       let mut iterated = false;
 

processor/signers/src/cosign/mod.rs

@@ -11,7 +11,7 @@ use serai_db::{DbTxn, Db};
 
 use messages::{sign::VariantSignId, coordinator::cosign_block_msg};
 
-use primitives::task::ContinuallyRan;
+use primitives::task::{DoesNotError, ContinuallyRan};
 
 use frost_attempt_manager::*;
 
@@ -51,7 +51,9 @@ impl<D: Db> CosignerTask<D> {
 }
 
 impl<D: Db> ContinuallyRan for CosignerTask<D> {
-  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
+  type Error = DoesNotError;
+
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, DoesNotError>> {
     async move {
       let mut iterated = false;
 

processor/signers/src/slash_report.rs

@@ -13,7 +13,7 @@ use serai_db::{DbTxn, Db};
 
 use messages::sign::VariantSignId;
 
-use primitives::task::ContinuallyRan;
+use primitives::task::{DoesNotError, ContinuallyRan};
 use scanner::ScannerFeed;
 
 use frost_attempt_manager::*;
@@ -52,7 +52,9 @@ impl<D: Db, S: ScannerFeed> SlashReportSignerTask<D, S> {
 }
 
 impl<D: Db, S: ScannerFeed> ContinuallyRan for SlashReportSignerTask<D, S> {
-  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
+  type Error = DoesNotError;
+
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, Self::Error>> {
     async move {
       let mut iterated = false;
 

processor/signers/src/transaction/mod.rs

@@ -92,7 +92,9 @@ impl<D: Db, ST: SignableTransaction, P: TransactionPublisher<TransactionFor<ST>>
 impl<D: Db, ST: SignableTransaction, P: TransactionPublisher<TransactionFor<ST>>> ContinuallyRan
   for TransactionSignerTask<D, ST, P>
 {
-  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, String>> {
+  type Error = P::EphemeralError;
+
+  fn run_iteration(&mut self) -> impl Send + Future<Output = Result<bool, Self::Error>> {
     async {
       let mut iterated = false;
 
@@ -222,11 +224,7 @@ impl<D: Db, ST: SignableTransaction, P: TransactionPublisher<TransactionFor<ST>>
           let tx = TransactionFor::<ST>::read(&mut tx_buf).unwrap();
           assert!(tx_buf.is_empty());
 
-          self
-            .publisher
-            .publish(tx)
-            .await
-            .map_err(|e| format!("couldn't re-broadcast transactions: {e:?}"))?;
+          self.publisher.publish(tx).await?;
         }
 
         self.last_publication = Instant::now();