improve precompile failure logging

This gets rid of the clippy warning, and will make actor debug logs a
bit more readable.

actors/evm/Cargo.toml

@@ -32,6 +32,7 @@ fil_actors_evm_shared = { workspace = true }
 hex = { workspace = true }
 hex-literal = { workspace = true }
 substrate-bn = { workspace = true }
+thiserror = { workspace = true }
 
 [dev-dependencies]
 hex = { workspace = true, features = ["serde"] }

actors/evm/shared/src/address.rs

@@ -19,12 +19,19 @@ impl From<U256> for EthAddress {
     }
 }
 
-impl std::fmt::Debug for EthAddress {
+impl std::fmt::Display for EthAddress {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str("0x")?;
         f.write_str(&hex::encode(self.0))
     }
 }
 
+impl std::fmt::Debug for EthAddress {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self)
+    }
+}
+
 impl From<EthAddress> for Address {
     fn from(addr: EthAddress) -> Self {
         From::from(&addr)

actors/evm/src/interpreter/instructions/call.rs

@@ -191,7 +191,7 @@ pub fn call_generic<RT: Runtime>(
             match precompiles::Precompiles::call_precompile(system, &dst, input_data, context) {
                 Ok(return_data) => (1, return_data),
                 Err(err) => {
-                    log::warn!(target: "evm", "Precompile failed: error {:?}", err);
+                    log::warn!(target: "evm", "call to precompile {} failed: {}", &dst, err);
                     // precompile failed, exit with reverted and no output
                     (0, vec![])
                 }

actors/evm/src/interpreter/precompiles/mod.rs

@@ -4,6 +4,7 @@ use fil_actors_evm_shared::{address::EthAddress, uints::U256};
 use fil_actors_runtime::{runtime::Runtime, ActorError};
 use fvm_shared::{address::Address, econ::TokenAmount};
 use substrate_bn::{CurveError, FieldError, GroupError};
+use thiserror::Error;
 
 use crate::reader::OverflowError;
 
@@ -111,15 +112,21 @@ impl<RT: Runtime> Precompiles<RT> {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, Error)]
 pub enum PrecompileError {
     // EVM precompile errors
+    #[error("EC curve error in data passed to precompile: {0:?}")]
     EcErr(CurveError),
+    #[error("incorrect input size to precompile")]
     IncorrectInputSize,
     // FVM precompile errors
+    #[error("invalid input to precompile")]
     InvalidInput,
+    #[error("calling convention forbidden for precompile")]
     CallForbidden,
+    #[error("transfering funds to precompile failed")]
     TransferFailed,
+    #[error("internal evm error when calling precompile: {0}")]
     VMError(ActorError),
 }