From dbb3fc30b300c2da7db6f68f660f6f0f17041412 Mon Sep 17 00:00:00 2001
From: slinkydeveloper <me@slinkydeveloper.com>
Date: Mon, 22 Sep 2025 12:27:20 +0200
Subject: [PATCH] Add better closed error

---
 Cargo.lock |  3 +--
 Cargo.toml |  2 +-
 src/lib.rs | 32 ++++++++++++++++++++++++++++++++
 3 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index ea91552..1f77727 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -516,8 +516,7 @@ dependencies = [
 [[package]]
 name = "restate-sdk-shared-core"
 version = "0.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c538c3af8f41229e3dd5aba4a31acdd84909c6653a3cc6b8ea64fd7fb54abb21"
+source = "git+https://github.com/restatedev/sdk-shared-core.git?rev=eafbe4729a4ae7fa74fd0fb32e29121b240e1e5e#eafbe4729a4ae7fa74fd0fb32e29121b240e1e5e"
 dependencies = [
  "base64 0.22.1",
  "bs58",
diff --git a/Cargo.toml b/Cargo.toml
index f6d2b57..537007f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,4 +14,4 @@ doc = false
 [dependencies]
 pyo3 = { version = "0.25.1", features = ["extension-module"] }
 tracing-subscriber = { version = "0.3", features = ["fmt", "env-filter"] }
-restate-sdk-shared-core = { version = "=0.6.0", features = ["request_identity", "sha2_random_seed"] }
+restate-sdk-shared-core = { git = "https://github.com/restatedev/sdk-shared-core.git", rev = "eafbe4729a4ae7fa74fd0fb32e29121b240e1e5e", features = ["request_identity", "sha2_random_seed"] }
diff --git a/src/lib.rs b/src/lib.rs
index ba7f555..45eef66 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
+use std::fmt;
 use pyo3::create_exception;
 use pyo3::prelude::*;
 use pyo3::types::{PyBytes, PyNone, PyString};
@@ -7,6 +8,7 @@ use restate_sdk_shared_core::{
     TerminalFailure, VMOptions, Value, CANCEL_NOTIFICATION_HANDLE, VM,
 };
 use std::time::{Duration, SystemTime};
+use restate_sdk_shared_core::fmt::{set_error_formatter, ErrorFormatter};
 
 // Current crate version
 const CURRENT_VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -158,6 +160,7 @@ impl From<PyFailure> for TerminalFailure {
         TerminalFailure {
             code: value.code,
             message: value.message,
+            metadata: vec![],
         }
     }
 }
@@ -751,6 +754,31 @@ impl PyIdentityVerifier {
     }
 }
 
+#[derive(Debug)]
+struct PythonErrorFormatter;
+
+impl ErrorFormatter for PythonErrorFormatter {
+    fn display_closed_error(&self, f: &mut fmt::Formatter<'_>, event: &str) -> fmt::Result {
+        write!(f, "Execution is suspended, but the handler is still attempting to make progress (calling '{event}'). This can happen:
+
+* If the SuspendedException is caught. Make sure you NEVER catch the SuspendedException, e.g. avoid:
+try:
+  # Code
+except:
+  # This catches all exceptions, including the SuspendedException!
+
+And use instead:
+try:
+  # Code
+except TerminalException:
+  # In Restate handlers you typically want to catch TerminalException
+
+Check https://docs.restate.dev/develop/python/durable-steps#run for more details on run error handling.
+
+* If you use the context after the handler completed, e.g. moving the context to another thread. Check https://docs.restate.dev/develop/python/concurrent-tasks for more details on how to create durable concurrent tasks in Python.")
+    }
+}
+
 #[pymodule]
 fn _internal(m: &Bound<'_, PyModule>) -> PyResult<()> {
     use tracing_subscriber::EnvFilter;
@@ -790,5 +818,9 @@ fn _internal(m: &Bound<'_, PyModule>) -> PyResult<()> {
         "CANCEL_NOTIFICATION_HANDLE",
         PyNotificationHandle::from(CANCEL_NOTIFICATION_HANDLE),
     )?;
+
+    // Set customized error formatter
+    set_error_formatter(PythonErrorFormatter);
+
     Ok(())
 }