New version

CHANGELOG.md

@@ -9,6 +9,13 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+## [0.24.17] - 2025-11-02
+
+### Fixed
+- Preserve captured backtraces when wrapping `AppError` instances through
+  `ResultExt::context` by sharing the snapshot instead of attempting to clone
+  `std::backtrace::Backtrace`.
+
 ## [0.24.16] - 2025-11-01
 
 ### Fixed

Cargo.toml

@@ -4,7 +4,7 @@
 
 [package]
 name = "masterror"
-version = "0.24.16"
+version = "0.24.17"
 rust-version = "1.90"
 edition = "2024"
 license = "MIT OR Apache-2.0"

README.md

@@ -80,9 +80,9 @@ The build script keeps the full feature snippet below in sync with
 
 ~~~toml
 [dependencies]
-masterror = { version = "0.24.16", default-features = false }
+masterror = { version = "0.24.17", default-features = false }
 # or with features:
-# masterror = { version = "0.24.16", features = [
+# masterror = { version = "0.24.17", features = [
 #   "std", "axum", "actix", "openapi",
 #   "serde_json", "tracing", "metrics", "backtrace",
 #   "sqlx", "sqlx-migrate", "reqwest", "redis",
@@ -459,4 +459,3 @@ assert_eq!(problem.grpc.expect("grpc").name, "UNAUTHENTICATED");
 
 MSRV: **1.90** · License: **MIT OR Apache-2.0** · No `unsafe`
 
-

WHY_MIGRATE.md

@@ -91,6 +91,10 @@ use masterror::prelude::*;
 fn process() -> AppResult<()> {
     ensure!(condition, AppError::bad_request("invalid input"));
 
+    // Simple context (anyhow-style)
+    database_call().context("db operation failed")?;
+
+    // Or structured context with metadata
     database_call()
         .ctx(|| Context::new(AppErrorKind::Database)
             .with(field::str("table", "users"))
@@ -100,7 +104,7 @@ fn process() -> AppResult<()> {
     fail!(AppError::internal("unrecoverable"));
 }
 
-// ✅ Same ergonomics as anyhow
+// ✅ Same ergonomics as anyhow (.context(), .chain(), .downcast_ref())
 // ✅ Plus: typed errors
 // ✅ Plus: structured metadata
 // ✅ Plus: automatic tracing
@@ -194,6 +198,32 @@ let err = AppError::database("query failed")
 // ✅ Zero boilerplate
 ```
 
+#### 5. Error Introspection (anyhow Parity)
+
+```rust
+// anyhow: type-safe error inspection
+if let Some(io_err) = err.downcast_ref::<io::Error>() {
+    match io_err.kind() {
+        io::ErrorKind::NotFound => /* handle */,
+        _ => /* other */
+    }
+}
+
+// masterror: same API, works with AppError
+use masterror::ResultExt;
+
+match database_op().context("db failed") {
+    Err(err) => {
+        if let Some(io_err) = err.downcast_ref::<io::Error>() {
+            // ✅ Type-safe downcasting
+            // ✅ Inspect wrapped error sources
+            // ✅ Full anyhow API compatibility
+        }
+    }
+    Ok(val) => val
+}
+```
+
 ## Migration Guide
 
 ### From thiserror
@@ -243,18 +273,29 @@ bail!("invalid input");
 fail!(AppError::bad_request("invalid input"));
 ```
 
-**Step 3:** Enhance context
+**Step 3:** Keep using .context() (it just works!)
 ```rust
-// Before
+// Before (anyhow)
 .context("db error")?
 
-// After
+// After (masterror) - identical API
+.context("db error")?
+
+// Or use structured context for better observability
 .ctx(|| Context::new(AppErrorKind::Database)
     .with(field::str("table", "users"))
 )?
 ```
 
-**Result:** Type-safe, structured, observable errors.
+**Step 4:** Error introspection works the same
+```rust
+// anyhow API still works
+if let Some(io_err) = err.downcast_ref::<io::Error>() {
+    // handle specific error type
+}
+```
+
+**Result:** Type-safe, structured, observable errors with zero API friction.
 
 ## Real-World Impact
 
@@ -346,7 +387,11 @@ Binary size: 944KB (vs thiserror 32KB, anyhow 566KB)
 
 - 📚 [Full Documentation](https://docs.rs/masterror)
 - 📊 [Benchmarks](BENCHMARKS.md)
-- 🔧 [Examples](examples/)
+- 🔧 **[Examples](examples/)** - See working code for:
+  - [Basic Usage](examples/basic_usage.rs) - Core error handling patterns
+  - [thiserror Compatibility](examples/derive_error.rs) - Drop-in replacement
+  - [Structured Metadata](examples/structured_metadata.rs) - Typed fields vs strings
+  - [Redaction](examples/redaction.rs) - GDPR-compliant privacy controls
 - 💬 [GitHub Issues](https://github.com/RAprogramm/masterror/issues)
 
 ---

examples/redaction.rs

@@ -0,0 +1,19 @@
+// SPDX-FileCopyrightText: 2025 RAprogramm <andrey.rozanov.vl@gmail.com>
+//
+// SPDX-License-Identifier: MIT
+
+//! Redaction example showing GDPR-compliant field masking.
+
+use masterror::{AppError, FieldRedaction, field};
+
+fn main() {
+    let err = AppError::bad_request("Invalid credentials")
+        .with_field(field::str("email", "user@example.com").with_redaction(FieldRedaction::Hash))
+        .with_field(field::str("ip", "192.168.1.100").with_redaction(FieldRedaction::Redact))
+        .with_field(field::str("session_id", "abc123"));
+
+    println!("=== Redacted Metadata ===\n");
+    for (key, value, redaction) in err.metadata().iter_with_redaction() {
+        println!("{key}: {value:?} [{redaction:?}]");
+    }
+}

src/app_error/core.rs

@@ -91,9 +91,9 @@ pub struct ErrorInner {
     pub details:            Option<String>,
     pub source:             Option<Arc<dyn CoreError + Send + Sync + 'static>>,
     #[cfg(feature = "backtrace")]
-    pub backtrace:          Option<Backtrace>,
+    pub backtrace:          Option<Arc<Backtrace>>,
     #[cfg(feature = "backtrace")]
-    pub captured_backtrace: OnceLock<Option<Backtrace>>,
+    pub captured_backtrace: OnceLock<Option<Arc<Backtrace>>>,
     telemetry_dirty:        AtomicBool,
     #[cfg(feature = "tracing")]
     tracing_dirty:          AtomicBool
@@ -110,9 +110,9 @@ const BACKTRACE_STATE_DISABLED: u8 = 2;
 static BACKTRACE_STATE: AtomicU8 = AtomicU8::new(BACKTRACE_STATE_UNSET);
 
 #[cfg(feature = "backtrace")]
-fn capture_backtrace_snapshot() -> Option<Backtrace> {
+fn capture_backtrace_snapshot() -> Option<Arc<Backtrace>> {
     if should_capture_backtrace() {
-        Some(Backtrace::capture())
+        Some(Arc::new(Backtrace::capture()))
     } else {
         None
     }
@@ -321,13 +321,13 @@ impl Error {
 
     #[cfg(feature = "backtrace")]
     fn capture_backtrace(&self) -> Option<&CapturedBacktrace> {
-        if let Some(backtrace) = self.backtrace.as_ref() {
+        if let Some(backtrace) = self.backtrace.as_deref() {
             return Some(backtrace);
         }
 
         self.captured_backtrace
             .get_or_init(capture_backtrace_snapshot)
-            .as_ref()
+            .as_deref()
     }
 
     #[cfg(not(feature = "backtrace"))]
@@ -336,7 +336,7 @@ impl Error {
     }
 
     #[cfg(feature = "backtrace")]
-    fn set_backtrace_slot(&mut self, backtrace: CapturedBacktrace) {
+    fn set_backtrace_slot(&mut self, backtrace: Arc<Backtrace>) {
         self.backtrace = Some(backtrace);
         self.captured_backtrace = OnceLock::new();
     }
@@ -574,6 +574,21 @@ impl Error {
     /// Attach a captured backtrace.
     #[must_use]
     pub fn with_backtrace(mut self, backtrace: CapturedBacktrace) -> Self {
+        #[cfg(feature = "backtrace")]
+        {
+            self.set_backtrace_slot(Arc::new(backtrace));
+        }
+
+        #[cfg(not(feature = "backtrace"))]
+        {
+            self.set_backtrace_slot(backtrace);
+        }
+        self.mark_dirty();
+        self
+    }
+
+    #[cfg(feature = "backtrace")]
+    pub(crate) fn with_shared_backtrace(mut self, backtrace: Arc<Backtrace>) -> Self {
         self.set_backtrace_slot(backtrace);
         self.mark_dirty();
         self
@@ -678,6 +693,18 @@ impl Error {
         self.capture_backtrace()
     }
 
+    #[cfg(feature = "backtrace")]
+    pub(crate) fn backtrace_shared(&self) -> Option<Arc<Backtrace>> {
+        if let Some(backtrace) = self.backtrace.as_ref() {
+            return Some(Arc::clone(backtrace));
+        }
+
+        self.captured_backtrace
+            .get_or_init(capture_backtrace_snapshot)
+            .as_ref()
+            .map(Arc::clone)
+    }
+
     /// Borrow the source if present.
     #[must_use]
     pub fn source_ref(&self) -> Option<&(dyn CoreError + Send + Sync + 'static)> {