refactor: use #[track_caller] directly instead of conditional cfg_attr

build.rs

@@ -1,8 +1,6 @@
 fn main() {
-    // track_caller is stable since Rust 1.46 (2020), so no version check needed
-    println!("cargo:rustc-cfg=track_caller");
+    // track_caller is always available with our MSRV (Rust ≥ 1.82)
 
     // Add check-cfg for conditional configurations
     println!("cargo:rustc-check-cfg=cfg(doc_cfg)");
-    println!("cargo:rustc-check-cfg=cfg(track_caller)");
 }

src/eyreish/context.rs

@@ -14,7 +14,7 @@ mod ext {
     use super::*;
 
     pub trait Diag {
-        #[cfg_attr(track_caller, track_caller)]
+        #[track_caller]
         fn ext_report<D>(self, msg: D) -> Report
         where
             D: Display + Send + Sync + 'static;
@@ -24,7 +24,7 @@ mod ext {
     where
         E: Diagnostic + Send + Sync + 'static,
     {
-        #[cfg_attr(track_caller, track_caller)]
+        #[track_caller]
         fn ext_report<D>(self, msg: D) -> Report
         where
             D: Display + Send + Sync + 'static,
@@ -34,7 +34,7 @@ mod ext {
     }
 
     impl Diag for Report {
-        #[cfg_attr(track_caller, track_caller)]
+        #[track_caller]
         fn ext_report<D>(self, msg: D) -> Report
         where
             D: Display + Send + Sync + 'static,
@@ -45,7 +45,7 @@ mod ext {
 }
 
 impl<T> WrapErr<T, Infallible> for Option<T> {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn wrap_err<D>(self, msg: D) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -56,7 +56,7 @@ impl<T> WrapErr<T, Infallible> for Option<T> {
         }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn wrap_err_with<D, F>(self, msg: F) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -68,7 +68,7 @@ impl<T> WrapErr<T, Infallible> for Option<T> {
         }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn context<D>(self, msg: D) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -76,7 +76,7 @@ impl<T> WrapErr<T, Infallible> for Option<T> {
         self.wrap_err(msg)
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn with_context<D, F>(self, msg: F) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -90,7 +90,7 @@ impl<T, E> WrapErr<T, E> for Result<T, E>
 where
     E: ext::Diag + Send + Sync + 'static,
 {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn wrap_err<D>(self, msg: D) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -101,7 +101,7 @@ where
         }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn wrap_err_with<D, F>(self, msg: F) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -113,7 +113,7 @@ where
         }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn context<D>(self, msg: D) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -121,7 +121,7 @@ where
         self.wrap_err(msg)
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn with_context<D, F>(self, msg: F) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,

src/eyreish/error.rs

@@ -23,7 +23,7 @@ impl Report {
     ///
     /// If the error type does not provide a backtrace, a backtrace will be
     /// created here to ensure that a backtrace exists.
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub fn new<E>(error: E) -> Self
     where
@@ -69,7 +69,7 @@ impl Report {
     ///         .await
     /// }
     /// ```
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub fn msg<M>(message: M) -> Self
     where
@@ -85,7 +85,7 @@ impl Report {
     ///
     /// Boxed `Diagnostic`s don't implement `Diagnostic` themselves due to trait coherence issues.
     /// This method allows you to create a `Report` from a boxed `Diagnostic`.
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     pub fn new_boxed(error: Box<dyn Diagnostic + Send + Sync + 'static>) -> Self {
         Report::from_boxed(error)
     }
@@ -111,7 +111,7 @@ impl Report {
         unsafe { Report::construct(error, vtable, handler) }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub(crate) fn from_adhoc<M>(message: M) -> Self
     where
@@ -136,7 +136,7 @@ impl Report {
         unsafe { Report::construct(error, vtable, handler) }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub(crate) fn from_msg<D, E>(msg: D, error: E) -> Self
     where
@@ -161,7 +161,7 @@ impl Report {
         unsafe { Report::construct(error, vtable, handler) }
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub(crate) fn from_boxed(error: Box<dyn Diagnostic + Send + Sync>) -> Self {
         use super::wrapper::BoxedError;

src/eyreish/into_diagnostic.rs

@@ -38,13 +38,13 @@ inaccessible. If you have a type implementing [`Diagnostic`] consider simply ret
 pub trait IntoDiagnostic<T, E> {
     /// Converts [`Result`] types that return regular [`std::error::Error`]s
     /// into a [`Result`] that returns a [`Diagnostic`].
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn into_diagnostic(self) -> Result<T, Report>;
 }
 
 #[cfg(feature = "std")]
 impl<T, E: std::error::Error + Send + Sync + 'static> IntoDiagnostic<T, E> for Result<T, E> {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn into_diagnostic(self) -> Result<T, Report> {
         self.map_err(|e| DiagnosticError(Box::new(e)).into())
     }
@@ -52,7 +52,7 @@ impl<T, E: std::error::Error + Send + Sync + 'static> IntoDiagnostic<T, E> for R
 
 #[cfg(not(feature = "std"))]
 impl<T, E: Error + Send + Sync + 'static> IntoDiagnostic<T, E> for Result<T, E> {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn into_diagnostic(self) -> Result<T, Report> {
         self.map_err(|e| DiagnosticError(Box::new(e)).into())
     }

src/eyreish/kind.rs

@@ -71,7 +71,7 @@ pub trait AdhocKind: Sized {
 impl<T> AdhocKind for &T where T: ?Sized + Display + Debug + Send + Sync + 'static {}
 
 impl Adhoc {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub fn new<M>(self, message: M) -> Report
     where
@@ -93,7 +93,7 @@ pub trait TraitKind: Sized {
 impl<E> TraitKind for E where E: Into<Report> {}
 
 impl Trait {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub fn new<E>(self, error: E) -> Report
     where
@@ -115,7 +115,7 @@ pub trait BoxedKind: Sized {
 impl BoxedKind for Box<dyn Diagnostic + Send + Sync> {}
 
 impl Boxed {
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub fn new(self, error: Box<dyn Diagnostic + Send + Sync>) -> Report {
         Report::from_boxed(error)

src/eyreish/mod.rs

@@ -105,7 +105,7 @@ pub(crate) fn capture_handler(error: &(dyn Diagnostic + 'static)) -> Box<dyn Rep
     hook(error)
 }
 
-#[cfg_attr(track_caller, track_caller)]
+#[track_caller]
 pub(crate) fn capture_handler_with_location(
     error: &(dyn Diagnostic + 'static),
 ) -> Box<dyn ReportHandler> {
@@ -115,16 +115,11 @@ pub(crate) fn capture_handler_with_location(
         DEFAULT.get().unwrap()
     });
 
-    #[cfg(track_caller)]
     {
         let mut handler = hook(error);
         handler.track_caller(core::panic::Location::caller());
         handler
     }
-    #[cfg(not(track_caller))]
-    {
-        hook(error)
-    }
 }
 
 fn get_default_printer(_err: &(dyn Diagnostic + 'static)) -> Box<dyn ReportHandler + 'static> {
@@ -454,27 +449,27 @@ pub type Result<T, E = Report> = core::result::Result<T, E>;
 ///     ```
 pub trait WrapErr<T, E>: context::private::Sealed {
     /// Wrap the error value with a new adhoc error
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn wrap_err<D>(self, msg: D) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static;
 
     /// Wrap the error value with a new adhoc error that is evaluated lazily
     /// only once an error does occur.
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn wrap_err_with<D, F>(self, f: F) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
         F: FnOnce() -> D;
 
     /// Compatibility re-export of `wrap_err()` for interop with `anyhow`
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn context<D>(self, msg: D) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static;
 
     /// Compatibility re-export of `wrap_err_with()` for interop with `anyhow`
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     fn with_context<D, F>(self, f: F) -> Result<T, Report>
     where
         D: Display + Send + Sync + 'static,
@@ -496,7 +491,7 @@ pub mod private {
         pub use super::super::kind::BoxedKind;
     }
 
-    #[cfg_attr(track_caller, track_caller)]
+    #[track_caller]
     #[cold]
     pub fn new_adhoc<M>(message: M) -> Report
     where