Upgrade anyhow to 1.0.68 am: 85b5e2f6c5

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/anyhow/+/2391492

Change-Id: I97439373ae5b8f9dea649ac32d583e45e8ffd61a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>

25 files changed, 271 insertions, 157 deletions

diff --git a/.cargo_vcs_info.json b/.cargo_vcs_info.json
index c4a86bc..c723f9d 100644
--- a/.cargo_vcs_info.json
+++ b/.cargo_vcs_info.json
@@ -1,6 +1,6 @@
 {
   "git": {
-    "sha1": "8f950ac0d696644b0ed17d73cb41c1ee30816cf3"
+    "sha1": "867763b8fce65656a754d8e0d84f0aa1c610613a"
   },
   "path_in_vcs": ""
 }
\ No newline at end of file
diff --git a/.clippy.toml b/.clippy.toml
index b32f6d5..78eb145 100644
--- a/.clippy.toml
+++ b/.clippy.toml
@@ -1 +1 @@
-msrv = "1.34.0"
+msrv = "1.38.0"
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index db58ee5..02f72f5 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -5,6 +5,9 @@ on:
   pull_request:
   schedule: [cron: "40 1 * * *"]
 
+permissions:
+  contents: read
+
 env:
   RUSTFLAGS: -Dwarnings
 
@@ -15,7 +18,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [nightly, beta, stable, 1.53.0]
+        rust: [nightly, beta, stable, 1.56.0]
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@master
@@ -32,7 +36,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        rust: [1.52.0, 1.51.0, 1.50.0, 1.42.0, 1.38.0]
+        rust: [1.52.0, 1.51.0, 1.50.0, 1.42.0, 1.39.0]
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@master
@@ -42,11 +47,12 @@ jobs:
       - run: cargo check
       - run: cargo check --no-default-features
       - run: cargo check --features backtrace
-        if: matrix.rust != '1.38.0'
+        if: matrix.rust != '1.39.0' && matrix.rust != '1.50.0'
 
   windows:
     name: Windows
     runs-on: windows-latest
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@stable
@@ -58,6 +64,7 @@ jobs:
     name: Clippy
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request'
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@nightly
@@ -68,11 +75,10 @@ jobs:
   miri:
     name: Miri
     runs-on: ubuntu-latest
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@nightly
-        with:
-          components: miri, rust-src
+      - uses: dtolnay/rust-toolchain@miri
       - run: cargo miri test
         env:
           MIRIFLAGS: -Zmiri-strict-provenance
@@ -81,6 +87,7 @@ jobs:
     name: Outdated
     runs-on: ubuntu-latest
     if: github.event_name != 'pull_request'
+    timeout-minutes: 45
     steps:
       - uses: actions/checkout@v3
       - uses: dtolnay/install@cargo-outdated
diff --git a/Android.bp b/Android.bp
index 45bde32..0582b9a 100644
--- a/Android.bp
+++ b/Android.bp
@@ -42,7 +42,7 @@ rust_test {
     host_supported: true,
     crate_name: "anyhow",
     cargo_env_compat: true,
-    cargo_pkg_version: "1.0.58",
+    cargo_pkg_version: "1.0.68",
     srcs: ["src/lib.rs"],
     test_suites: ["general-tests"],
     auto_gen_config: true,
@@ -64,7 +64,7 @@ rust_defaults {
     name: "anyhow_test_defaults",
     crate_name: "anyhow",
     cargo_env_compat: true,
-    cargo_pkg_version: "1.0.58",
+    cargo_pkg_version: "1.0.68",
     test_suites: ["general-tests"],
     auto_gen_config: true,
     edition: "2018",
@@ -140,6 +140,16 @@ rust_test {
 }
 
 rust_test {
+    name: "anyhow_test_tests_test_ffi",
+    defaults: ["anyhow_test_defaults"],
+    host_supported: true,
+    srcs: ["tests/test_ffi.rs"],
+    test_options: {
+        unit_test: true,
+    },
+}
+
+rust_test {
     name: "anyhow_test_tests_test_fmt",
     defaults: ["anyhow_test_defaults"],
     host_supported: true,
@@ -184,7 +194,7 @@ rust_library {
     host_supported: true,
     crate_name: "anyhow",
     cargo_env_compat: true,
-    cargo_pkg_version: "1.0.58",
+    cargo_pkg_version: "1.0.68",
     srcs: ["src/lib.rs"],
     edition: "2018",
     features: [
@@ -198,3 +208,4 @@ rust_library {
     vendor_available: true,
     min_sdk_version: "29",
 }
+
diff --git a/Cargo.toml b/Cargo.toml
index c20ab5f..6fca217 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,14 +11,21 @@
 
 [package]
 edition = "2018"
-rust-version = "1.38"
+rust-version = "1.39"
 name = "anyhow"
-version = "1.0.58"
+version = "1.0.68"
 authors = ["David Tolnay <dtolnay@gmail.com>"]
 description = "Flexible concrete Error type built on std::error::Error"
 documentation = "https://docs.rs/anyhow"
 readme = "README.md"
-categories = ["rust-patterns"]
+keywords = [
+    "error",
+    "error-handling",
+]
+categories = [
+    "rust-patterns",
+    "no-std",
+]
 license = "MIT OR Apache-2.0"
 repository = "https://github.com/dtolnay/anyhow"
 
@@ -29,6 +36,9 @@ rustdoc-args = [
     "doc_cfg",
 ]
 
+[lib]
+doc-scrape-examples = false
+
 [dependencies.backtrace]
 version = "0.3.51"
 optional = true
@@ -48,7 +58,7 @@ features = ["full"]
 version = "1.0"
 
 [dev-dependencies.trybuild]
-version = "1.0.49"
+version = "1.0.66"
 features = ["diff"]
 
 [features]
diff --git a/Cargo.toml.orig b/Cargo.toml.orig
index 7232d17..952219e 100644
--- a/Cargo.toml.orig
+++ b/Cargo.toml.orig
@@ -1,15 +1,15 @@
 [package]
 name = "anyhow"
-version = "1.0.58" # remember to update html_root_url
+version = "1.0.68" # remember to update html_root_url
 authors = ["David Tolnay <dtolnay@gmail.com>"]
+categories = ["rust-patterns", "no-std"]
+description = "Flexible concrete Error type built on std::error::Error"
+documentation = "https://docs.rs/anyhow"
 edition = "2018"
-rust-version = "1.38"
+keywords = ["error", "error-handling"]
 license = "MIT OR Apache-2.0"
-description = "Flexible concrete Error type built on std::error::Error"
 repository = "https://github.com/dtolnay/anyhow"
-documentation = "https://docs.rs/anyhow"
-readme = "README.md"
-categories = ["rust-patterns"]
+rust-version = "1.39"
 
 [features]
 default = ["std"]
@@ -23,7 +23,10 @@ futures = { version = "0.3", default-features = false }
 rustversion = "1.0.6"
 syn = { version = "1.0", features = ["full"] }
 thiserror = "1.0"
-trybuild = { version = "1.0.49", features = ["diff"] }
+trybuild = { version = "1.0.66", features = ["diff"] }
+
+[lib]
+doc-scrape-examples = false
 
 [package.metadata.docs.rs]
 targets = ["x86_64-unknown-linux-gnu"]
diff --git a/METADATA b/METADATA
index 5333803..fcc4813 100644
--- a/METADATA
+++ b/METADATA
@@ -1,3 +1,7 @@
+# This project was upgraded with external_updater.
+# Usage: tools/external_updater/updater.sh update rust/crates/anyhow
+# For more info, check https://cs.android.com/android/platform/superproject/+/master:tools/external_updater/README.md
+
 name: "anyhow"
 description: "Flexible concrete Error type built on std::error::Error"
 third_party {
@@ -7,13 +11,13 @@ third_party {
   }
   url {
     type: ARCHIVE
-    value: "https://static.crates.io/crates/anyhow/anyhow-1.0.58.crate"
+    value: "https://static.crates.io/crates/anyhow/anyhow-1.0.68.crate"
   }
-  version: "1.0.58"
+  version: "1.0.68"
   license_type: NOTICE
   last_upgrade_date {
-    year: 2022
-    month: 6
-    day: 23
+    year: 2023
+    month: 1
+    day: 17
   }
 }
diff --git a/README.md b/README.md
index 7785279..6380c1c 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,7 @@ Anyhow&ensp;¯\\\_(°ペ)\_/¯
 [<img alt="github" src="https://img.shields.io/badge/github-dtolnay/anyhow-8da0cb?style=for-the-badge&labelColor=555555&logo=github" height="20">](https://github.com/dtolnay/anyhow)
 [<img alt="crates.io" src="https://img.shields.io/crates/v/anyhow.svg?style=for-the-badge&color=fc8d62&logo=rust" height="20">](https://crates.io/crates/anyhow)
 [<img alt="docs.rs" src="https://img.shields.io/badge/docs.rs-anyhow-66c2a5?style=for-the-badge&labelColor=555555&logo=docs.rs" height="20">](https://docs.rs/anyhow)
-[<img alt="build status" src="https://img.shields.io/github/workflow/status/dtolnay/anyhow/CI/master?style=for-the-badge" height="20">](https://github.com/dtolnay/anyhow/actions?query=branch%3Amaster)
+[<img alt="build status" src="https://img.shields.io/github/actions/workflow/status/dtolnay/anyhow/ci.yml?branch=master&style=for-the-badge" height="20">](https://github.com/dtolnay/anyhow/actions?query=branch%3Amaster)
 
 This library provides [`anyhow::Error`][Error], a trait object based error type
 for easy idiomatic error handling in Rust applications.
@@ -16,7 +16,7 @@ for easy idiomatic error handling in Rust applications.
 anyhow = "1.0"
 ```
 
-*Compiler support: requires rustc 1.38+*
+*Compiler support: requires rustc 1.39+*
 
 <br>
 
diff --git a/build.rs b/build.rs
index cd79927..3800683 100644
--- a/build.rs
+++ b/build.rs
@@ -15,15 +15,17 @@ compile_error! {
 // type. If the current toolchain is able to compile it, we go ahead and use
 // backtrace in anyhow.
 const PROBE: &str = r#"
-    #![feature(backtrace)]
-    #![allow(dead_code)]
+    #![feature(error_generic_member_access, provide_any)]
 
+    use std::any::{Demand, Provider};
     use std::backtrace::{Backtrace, BacktraceStatus};
     use std::error::Error;
     use std::fmt::{self, Display};
 
     #[derive(Debug)]
-    struct E;
+    struct E {
+        backtrace: Backtrace,
+    }
 
     impl Display for E {
         fn fmt(&self, _formatter: &mut fmt::Formatter) -> fmt::Result {
@@ -32,14 +34,26 @@ const PROBE: &str = r#"
     }
 
     impl Error for E {
-        fn backtrace(&self) -> Option<&Backtrace> {
-            let backtrace = Backtrace::capture();
-            match backtrace.status() {
-                BacktraceStatus::Captured | BacktraceStatus::Disabled | _ => {}
-            }
-            unimplemented!()
+        fn provide<'a>(&'a self, demand: &mut Demand<'a>) {
+            demand.provide_ref(&self.backtrace);
         }
     }
+
+    struct P;
+
+    impl Provider for P {
+        fn provide<'a>(&'a self, _demand: &mut Demand<'a>) {}
+    }
+
+    const _: fn() = || {
+        let backtrace: Backtrace = Backtrace::capture();
+        let status: BacktraceStatus = backtrace.status();
+        match status {
+            BacktraceStatus::Captured | BacktraceStatus::Disabled | _ => {}
+        }
+    };
+
+    const _: fn(&dyn Error) -> Option<&Backtrace> = |err| err.request_ref::<Backtrace>();
 "#;
 
 fn main() {
@@ -71,7 +85,7 @@ fn compile_probe() -> Option<ExitStatus> {
     fs::write(&probefile, PROBE).ok()?;
 
     // Make sure to pick up Cargo rustc configuration.
-    let mut cmd = if let Some(wrapper) = env::var_os("CARGO_RUSTC_WRAPPER") {
+    let mut cmd = if let Some(wrapper) = env::var_os("RUSTC_WRAPPER") {
         let mut cmd = Command::new(wrapper);
         // The wrapper's first argument is supposed to be the path to rustc.
         cmd.arg(rustc);
@@ -89,6 +103,10 @@ fn compile_probe() -> Option<ExitStatus> {
         .arg(out_dir)
         .arg(probefile);
 
+    if let Some(target) = env::var_os("TARGET") {
+        cmd.arg("--target").arg(target);
+    }
+
     // If Cargo wants to set RUSTFLAGS, use that.
     if let Ok(rustflags) = env::var("CARGO_ENCODED_RUSTFLAGS") {
         if !rustflags.is_empty() {
diff --git a/cargo2android.json b/cargo2android.json
index adb0d01..41b0f7c 100644
--- a/cargo2android.json
+++ b/cargo2android.json
@@ -1,6 +1,7 @@
 {
   "dependencies": true,
   "dependency-blocklist": [
+    "backtrace",
     "rustversion",
     "syn",
     "trybuild"
@@ -14,5 +15,8 @@
     "tests/test_ensure.rs"
   ],
   "tests": true,
-  "vendor-available": true
+  "vendor-available": true,
+  "cfg-blocklist": [
+    "backtrace"
+  ]
 }
diff --git a/src/backtrace.rs b/src/backtrace.rs
index e4c9076..23c0c85 100644
--- a/src/backtrace.rs
+++ b/src/backtrace.rs
@@ -38,7 +38,7 @@ macro_rules! backtrace {
 #[cfg(backtrace)]
 macro_rules! backtrace_if_absent {
     ($err:expr) => {
-        match $err.backtrace() {
+        match ($err as &dyn std::error::Error).request_ref::<std::backtrace::Backtrace>() {
             Some(_) => None,
             None => backtrace!(),
         }
diff --git a/src/context.rs b/src/context.rs
index c228413..9df8693 100644
--- a/src/context.rs
+++ b/src/context.rs
@@ -4,7 +4,7 @@ use core::convert::Infallible;
 use core::fmt::{self, Debug, Display, Write};
 
 #[cfg(backtrace)]
-use std::backtrace::Backtrace;
+use std::any::{Demand, Provider};
 
 mod ext {
     use super::*;
@@ -24,7 +24,7 @@ mod ext {
         where
             C: Display + Send + Sync + 'static,
         {
-            let backtrace = backtrace_if_absent!(self);
+            let backtrace = backtrace_if_absent!(&self);
             Error::from_context(context, self, backtrace)
         }
     }
@@ -47,7 +47,12 @@ where
     where
         C: Display + Send + Sync + 'static,
     {
-        self.map_err(|error| error.ext_context(context))
+        // Not using map_err to save 2 useless frames off the captured backtrace
+        // in ext_context.
+        match self {
+            Ok(ok) => Ok(ok),
+            Err(error) => Err(error.ext_context(context)),
+        }
     }
 
     fn with_context<C, F>(self, context: F) -> Result<T, Error>
@@ -55,7 +60,10 @@ where
         C: Display + Send + Sync + 'static,
         F: FnOnce() -> C,
     {
-        self.map_err(|error| error.ext_context(context()))
+        match self {
+            Ok(ok) => Ok(ok),
+            Err(error) => Err(error.ext_context(context())),
+        }
     }
 }
 
@@ -84,7 +92,12 @@ impl<T> Context<T, Infallible> for Option<T> {
     where
         C: Display + Send + Sync + 'static,
     {
-        self.ok_or_else(|| Error::from_display(context, backtrace!()))
+        // Not using ok_or_else to save 2 useless frames off the captured
+        // backtrace.
+        match self {
+            Some(ok) => Ok(ok),
+            None => Err(Error::from_display(context, backtrace!())),
+        }
     }
 
     fn with_context<C, F>(self, context: F) -> Result<T, Error>
@@ -92,7 +105,10 @@ impl<T> Context<T, Infallible> for Option<T> {
         C: Display + Send + Sync + 'static,
         F: FnOnce() -> C,
     {
-        self.ok_or_else(|| Error::from_display(context(), backtrace!()))
+        match self {
+            Some(ok) => Ok(ok),
+            None => Err(Error::from_display(context(), backtrace!())),
+        }
     }
 }
 
@@ -123,28 +139,28 @@ where
     C: Display,
     E: StdError + 'static,
 {
-    #[cfg(backtrace)]
-    fn backtrace(&self) -> Option<&Backtrace> {
-        self.error.backtrace()
-    }
-
     fn source(&self) -> Option<&(dyn StdError + 'static)> {
         Some(&self.error)
     }
+
+    #[cfg(backtrace)]
+    fn provide<'a>(&'a self, demand: &mut Demand<'a>) {
+        StdError::provide(&self.error, demand);
+    }
 }
 
 impl<C> StdError for ContextError<C, Error>
 where
     C: Display,
 {
-    #[cfg(backtrace)]
-    fn backtrace(&self) -> Option<&Backtrace> {
-        Some(self.error.backtrace())
-    }
-
     fn source(&self) -> Option<&(dyn StdError + 'static)> {
         Some(unsafe { crate::ErrorImpl::error(self.error.inner.by_ref()) })
     }
+
+    #[cfg(backtrace)]
+    fn provide<'a>(&'a self, demand: &mut Demand<'a>) {
+        Provider::provide(&self.error, demand);
+    }
 }
 
 struct Quoted<C>(C);
diff --git a/src/ensure.rs b/src/ensure.rs
index 80bdab7..0ab4471 100644
--- a/src/ensure.rs
+++ b/src/ensure.rs
@@ -788,15 +788,15 @@ macro_rules! __fancy_ensure {
             (lhs, rhs) => {
                 if !(lhs $op rhs) {
                     #[allow(unused_imports)]
-                    use $crate::private::{BothDebug, NotBothDebug};
+                    use $crate::__private::{BothDebug, NotBothDebug};
                     return Err((lhs, rhs).__dispatch_ensure(
-                        $crate::private::concat!(
+                        $crate::__private::concat!(
                             "Condition failed: `",
-                            $crate::private::stringify!($lhs),
+                            $crate::__private::stringify!($lhs),
                             " ",
-                            $crate::private::stringify!($op),
+                            $crate::__private::stringify!($op),
                             " ",
-                            $crate::private::stringify!($rhs),
+                            $crate::__private::stringify!($rhs),
                             "`",
                         ),
                     ));
@@ -811,24 +811,24 @@ macro_rules! __fancy_ensure {
 macro_rules! __fallback_ensure {
     ($cond:expr $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::Error::msg(
-                $crate::private::concat!("Condition failed: `", $crate::private::stringify!($cond), "`")
+            return $crate::__private::Err($crate::Error::msg(
+                $crate::__private::concat!("Condition failed: `", $crate::__private::stringify!($cond), "`")
             ));
         }
     };
     ($cond:expr, $msg:literal $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::__anyhow!($msg));
+            return $crate::__private::Err($crate::__anyhow!($msg));
         }
     };
     ($cond:expr, $err:expr $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::__anyhow!($err));
+            return $crate::__private::Err($crate::__anyhow!($err));
         }
     };
     ($cond:expr, $fmt:expr, $($arg:tt)*) => {
         if !$cond {
-            return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*));
+            return $crate::__private::Err($crate::__anyhow!($fmt, $($arg)*));
         }
     };
 }
diff --git a/src/error.rs b/src/error.rs
index 0971146..9f6ce8c 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -5,6 +5,8 @@ use crate::ptr::Mut;
 use crate::ptr::{Own, Ref};
 use crate::{Error, StdError};
 use alloc::boxed::Box;
+#[cfg(backtrace)]
+use core::any::Demand;
 use core::any::TypeId;
 use core::fmt::{self, Debug, Display};
 use core::mem::ManuallyDrop;
@@ -31,7 +33,7 @@ impl Error {
     where
         E: StdError + Send + Sync + 'static,
     {
-        let backtrace = backtrace_if_absent!(error);
+        let backtrace = backtrace_if_absent!(&error);
         Error::from_std(error, backtrace)
     }
 
@@ -522,6 +524,18 @@ impl Error {
     }
 }
 
+#[cfg(backtrace)]
+impl std::any::Provider for Error {
+    // Called by thiserror when you have `#[source] anyhow::Error`. This provide
+    // implementation includes the anyhow::Error's Backtrace if any, unlike
+    // deref'ing to dyn Error where the provide implementation would include
+    // only the original error's Backtrace from before it got wrapped into an
+    // anyhow::Error.
+    fn provide<'a>(&'a self, demand: &mut Demand<'a>) {
+        unsafe { ErrorImpl::provide(self.inner.by_ref(), demand) }
+    }
+}
+
 #[cfg(feature = "std")]
 #[cfg_attr(doc_cfg, doc(cfg(feature = "std")))]
 impl<E> From<E> for Error
@@ -530,7 +544,7 @@ where
 {
     #[cold]
     fn from(error: E) -> Self {
-        let backtrace = backtrace_if_absent!(error);
+        let backtrace = backtrace_if_absent!(&error);
         Error::from_std(error, backtrace)
     }
 }
@@ -886,13 +900,21 @@ impl ErrorImpl {
             .as_ref()
             .or_else(|| {
                 #[cfg(backtrace)]
-                return Self::error(this).backtrace();
-                #[cfg(all(not(backtrace), feature = "backtrace"))]
+                return Self::error(this).request_ref::<Backtrace>();
+                #[cfg(not(backtrace))]
                 return (vtable(this.ptr).object_backtrace)(this);
             })
             .expect("backtrace capture failed")
     }
 
+    #[cfg(backtrace)]
+    unsafe fn provide<'a>(this: Ref<'a, Self>, demand: &mut Demand<'a>) {
+        if let Some(backtrace) = &this.deref().backtrace {
+            demand.provide_ref(backtrace);
+        }
+        Self::error(this).provide(demand);
+    }
+
     #[cold]
     pub(crate) unsafe fn chain(this: Ref<Self>) -> Chain {
         Chain::new(Self::error(this))
@@ -903,14 +925,14 @@ impl<E> StdError for ErrorImpl<E>
 where
     E: StdError,
 {
-    #[cfg(backtrace)]
-    fn backtrace(&self) -> Option<&Backtrace> {
-        Some(unsafe { ErrorImpl::backtrace(self.erase()) })
-    }
-
     fn source(&self) -> Option<&(dyn StdError + 'static)> {
         unsafe { ErrorImpl::error(self.erase()).source() }
     }
+
+    #[cfg(backtrace)]
+    fn provide<'a>(&'a self, demand: &mut Demand<'a>) {
+        unsafe { ErrorImpl::provide(self.erase(), demand) }
+    }
 }
 
 impl<E> Debug for ErrorImpl<E>
diff --git a/src/kind.rs b/src/kind.rs
index 5985705..f47fe44 100644
--- a/src/kind.rs
+++ b/src/kind.rs
@@ -40,7 +40,7 @@
 // The anyhow! macro will set up the call in this form:
 //
 //     #[allow(unused_imports)]
-//     use $crate::private::{AdhocKind, TraitKind};
+//     use $crate::__private::{AdhocKind, TraitKind};
 //     let error = $msg;
 //     (&error).anyhow_kind().new(error)
 
@@ -110,7 +110,7 @@ impl BoxedKind for Box<dyn StdError + Send + Sync> {}
 impl Boxed {
     #[cold]
     pub fn new(self, error: Box<dyn StdError + Send + Sync>) -> Error {
-        let backtrace = backtrace_if_absent!(error);
+        let backtrace = backtrace_if_absent!(&*error);
         Error::from_boxed(error, backtrace)
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index dbd088a..3510d19 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -210,14 +210,15 @@
 //! will require an explicit `.map_err(Error::msg)` when working with a
 //! non-Anyhow error type inside a function that returns Anyhow's error type.
 
-#![doc(html_root_url = "https://docs.rs/anyhow/1.0.58")]
-#![cfg_attr(backtrace, feature(backtrace))]
+#![doc(html_root_url = "https://docs.rs/anyhow/1.0.68")]
+#![cfg_attr(backtrace, feature(error_generic_member_access, provide_any))]
 #![cfg_attr(doc_cfg, feature(doc_cfg))]
 #![cfg_attr(not(feature = "std"), no_std)]
 #![deny(dead_code, unused_imports, unused_mut)]
 #![allow(
     clippy::doc_markdown,
     clippy::enum_glob_use,
+    clippy::explicit_auto_deref,
     clippy::missing_errors_doc,
     clippy::missing_panics_doc,
     clippy::module_name_repetitions,
@@ -633,7 +634,7 @@ pub fn Ok<T>(t: T) -> Result<T> {
 
 // Not public API. Referenced by macro-generated code.
 #[doc(hidden)]
-pub mod private {
+pub mod __private {
     use crate::Error;
     use alloc::fmt;
     use core::fmt::Arguments;
diff --git a/src/macros.rs b/src/macros.rs
index 5dc1383..6dd2274 100644
--- a/src/macros.rs
+++ b/src/macros.rs
@@ -55,13 +55,13 @@
 #[macro_export]
 macro_rules! bail {
     ($msg:literal $(,)?) => {
-        return $crate::private::Err($crate::__anyhow!($msg))
+        return $crate::__private::Err($crate::__anyhow!($msg))
     };
     ($err:expr $(,)?) => {
-        return $crate::private::Err($crate::__anyhow!($err))
+        return $crate::__private::Err($crate::__anyhow!($err))
     };
     ($fmt:expr, $($arg:tt)*) => {
-        return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*))
+        return $crate::__private::Err($crate::__anyhow!($fmt, $($arg)*))
     };
 }
 
@@ -120,24 +120,24 @@ macro_rules! bail {
 macro_rules! ensure {
     ($cond:expr $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::Error::msg(
-                $crate::private::concat!("Condition failed: `", $crate::private::stringify!($cond), "`")
+            return $crate::__private::Err($crate::Error::msg(
+                $crate::__private::concat!("Condition failed: `", $crate::__private::stringify!($cond), "`")
             ));
         }
     };
     ($cond:expr, $msg:literal $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::__anyhow!($msg));
+            return $crate::__private::Err($crate::__anyhow!($msg));
         }
     };
     ($cond:expr, $err:expr $(,)?) => {
         if !$cond {
-            return $crate::private::Err($crate::__anyhow!($err));
+            return $crate::__private::Err($crate::__anyhow!($err));
         }
     };
     ($cond:expr, $fmt:expr, $($arg:tt)*) => {
         if !$cond {
-            return $crate::private::Err($crate::__anyhow!($fmt, $($arg)*));
+            return $crate::__private::Err($crate::__anyhow!($fmt, $($arg)*));
         }
     };
 }
@@ -189,14 +189,14 @@ macro_rules! ensure {
 #[macro_export]
 macro_rules! anyhow {
     ($msg:literal $(,)?) => {
-        $crate::private::must_use({
-            let error = $crate::private::format_err($crate::private::format_args!($msg));
+        $crate::__private::must_use({
+            let error = $crate::__private::format_err($crate::__private::format_args!($msg));
             error
         })
     };
     ($err:expr $(,)?) => {
-        $crate::private::must_use({
-            use $crate::private::kind::*;
+        $crate::__private::must_use({
+            use $crate::__private::kind::*;
             let error = match $err {
                 error => (&error).anyhow_kind().new(error),
             };
@@ -204,7 +204,7 @@ macro_rules! anyhow {
         })
     };
     ($fmt:expr, $($arg:tt)*) => {
-        $crate::Error::msg($crate::private::format!($fmt, $($arg)*))
+        $crate::Error::msg($crate::__private::format!($fmt, $($arg)*))
     };
 }
 
@@ -215,17 +215,17 @@ macro_rules! anyhow {
 #[macro_export]
 macro_rules! __anyhow {
     ($msg:literal $(,)?) => ({
-        let error = $crate::private::format_err($crate::private::format_args!($msg));
+        let error = $crate::__private::format_err($crate::__private::format_args!($msg));
         error
     });
     ($err:expr $(,)?) => ({
-        use $crate::private::kind::*;
+        use $crate::__private::kind::*;
         let error = match $err {
             error => (&error).anyhow_kind().new(error),
         };
         error
     });
     ($fmt:expr, $($arg:tt)*) => {
-        $crate::Error::msg($crate::private::format!($fmt, $($arg)*))
+        $crate::Error::msg($crate::__private::format!($fmt, $($arg)*))
     };
 }
diff --git a/src/wrapper.rs b/src/wrapper.rs
index 3ebe51a..5f18a50 100644
--- a/src/wrapper.rs
+++ b/src/wrapper.rs
@@ -1,6 +1,9 @@
 use crate::StdError;
 use core::fmt::{self, Debug, Display};
 
+#[cfg(backtrace)]
+use std::any::Demand;
+
 #[repr(transparent)]
 pub struct MessageError<M>(pub M);
 
@@ -67,12 +70,12 @@ impl Display for BoxedError {
 
 #[cfg(feature = "std")]
 impl StdError for BoxedError {
-    #[cfg(backtrace)]
-    fn backtrace(&self) -> Option<&crate::backtrace::Backtrace> {
-        self.0.backtrace()
-    }
-
     fn source(&self) -> Option<&(dyn StdError + 'static)> {
         self.0.source()
     }
+
+    #[cfg(backtrace)]
+    fn provide<'a>(&'a self, demand: &mut Demand<'a>) {
+        self.0.provide(demand);
+    }
 }
diff --git a/tests/test_downcast.rs b/tests/test_downcast.rs
index 7fb063f..b4470d5 100644
--- a/tests/test_downcast.rs
+++ b/tests/test_downcast.rs
@@ -1,4 +1,4 @@
-#![allow(clippy::wildcard_imports)]
+#![allow(clippy::assertions_on_result_states, clippy::wildcard_imports)]
 
 mod common;
 mod drop;
diff --git a/tests/test_ensure.rs b/tests/test_ensure.rs
index 4bb12f9..de867f7 100644
--- a/tests/test_ensure.rs
+++ b/tests/test_ensure.rs
@@ -1,13 +1,13 @@
 #![allow(
+    clippy::bool_to_int_with_if,
     clippy::diverging_sub_expression,
     clippy::if_same_then_else,
     clippy::ifs_same_cond,
     clippy::items_after_statements,
     clippy::let_and_return,
-    clippy::let_underscore_drop,
-    clippy::logic_bug,
     clippy::match_bool,
     clippy::never_loop,
+    clippy::overly_complex_bool_expr,
     clippy::redundant_closure_call,
     clippy::redundant_pattern_matching,
     clippy::too_many_lines,
@@ -17,10 +17,12 @@
     irrefutable_let_patterns
 )]
 
+use self::Enum::Generic;
 use anyhow::{anyhow, ensure, Chain, Error, Result};
-use std::fmt::Debug;
+use std::fmt::{self, Debug};
 use std::iter;
 use std::marker::{PhantomData, PhantomData as P};
+use std::mem;
 use std::ops::Add;
 use std::ptr;
 
@@ -43,6 +45,24 @@ trait Trait: Sized {
 
 impl<T> Trait for T {}
 
+enum Enum<T: ?Sized> {
+    #[allow(dead_code)]
+    Thing(PhantomData<T>),
+    Generic,
+}
+
+impl<T: ?Sized> PartialEq for Enum<T> {
+    fn eq(&self, rhs: &Self) -> bool {
+        mem::discriminant(self) == mem::discriminant(rhs)
+    }
+}
+
+impl<T: ?Sized> Debug for Enum<T> {
+    fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
+        formatter.write_str("Generic")
+    }
+}
+
 #[track_caller]
 fn assert_err<T: Debug>(result: impl FnOnce() -> Result<T>, expected: &'static str) {
     let actual = result().unwrap_err().to_string();
@@ -355,27 +375,27 @@ fn test_path() {
     let test = || Ok(ensure!(E::U::<u8,>>E::U));
     assert_err(test, "Condition failed: `E::U::<u8> > E::U` (U vs U)");
 
-    let test = || Ok(ensure!(PhantomData::<dyn Debug + Sync> != PhantomData));
+    let test = || Ok(ensure!(Generic::<dyn Debug + Sync> != Generic));
     assert_err(
         test,
-        "Condition failed: `PhantomData::<dyn Debug + Sync> != PhantomData` (PhantomData vs PhantomData)",
+        "Condition failed: `Generic::<dyn Debug + Sync> != Generic` (Generic vs Generic)",
     );
 
-    let test = || Ok(ensure!(PhantomData::<dyn Fn() + Sync> != PhantomData));
+    let test = || Ok(ensure!(Generic::<dyn Fn() + Sync> != Generic));
     assert_err(
         test,
-        "Condition failed: `PhantomData::<dyn Fn() + Sync> != PhantomData` (PhantomData vs PhantomData)",
+        "Condition failed: `Generic::<dyn Fn() + Sync> != Generic` (Generic vs Generic)",
     );
 
     #[rustfmt::skip]
     let test = || {
         Ok(ensure!(
-            PhantomData::<dyn Fn::() + ::std::marker::Sync> != PhantomData
+            Generic::<dyn Fn::() + ::std::marker::Sync> != Generic
         ))
     };
     assert_err(
         test,
-        "Condition failed: `PhantomData::<dyn Fn() + ::std::marker::Sync> != PhantomData` (PhantomData vs PhantomData)",
+        "Condition failed: `Generic::<dyn Fn() + ::std::marker::Sync> != Generic` (Generic vs Generic)",
     );
 }
 
@@ -408,7 +428,7 @@ fn test_trailer() {
     let test = || Ok(ensure!(PhantomData::<u8> {} != PhantomData));
     assert_err(
         test,
-        "Condition failed: `PhantomData::<u8> {} != PhantomData` (PhantomData vs PhantomData)",
+        "Condition failed: `PhantomData::<u8> {} != PhantomData` (PhantomData<u8> vs PhantomData<u8>)",
     );
 
     let result = Ok::<_, Error>(1);
@@ -596,7 +616,7 @@ fn test_as() {
     };
     assert_err(
         test,
-        "Condition failed: `PhantomData as PhantomData<<i32 as ToOwned>::Owned> != PhantomData` (PhantomData vs PhantomData)",
+        "Condition failed: `PhantomData as PhantomData<<i32 as ToOwned>::Owned> != PhantomData` (PhantomData<i32> vs PhantomData<i32>)",
     );
 
     macro_rules! int {
diff --git a/tests/test_macros.rs b/tests/test_macros.rs
index 1ac3970..a3342ab 100644
--- a/tests/test_macros.rs
+++ b/tests/test_macros.rs
@@ -1,4 +1,5 @@
 #![allow(
+    clippy::assertions_on_result_states,
     clippy::eq_op,
     clippy::items_after_statements,
     clippy::needless_pass_by_value,
diff --git a/tests/ui/empty-ensure.stderr b/tests/ui/empty-ensure.stderr
index b500de9..bf0229a 100644
--- a/tests/ui/empty-ensure.stderr
+++ b/tests/ui/empty-ensure.stderr
@@ -4,4 +4,9 @@ error: unexpected end of macro invocation
 4 |     ensure!();
   |     ^^^^^^^^^ missing tokens in macro arguments
   |
-  = note: this error originates in the macro `$crate::__parse_ensure` (in Nightly builds, run with -Z macro-backtrace for more info)
+note: while trying to match meta-variable `$cond:expr`
+ --> src/ensure.rs
+  |
+  |     ($cond:expr $(,)?) => {
+  |      ^^^^^^^^^^
+  = note: this error originates in the macro `$crate::__parse_ensure` which comes from the expansion of the macro `ensure` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/ui/must-use.stderr b/tests/ui/must-use.stderr
index e9ee24b..e10bde4 100644
--- a/tests/ui/must-use.stderr
+++ b/tests/ui/must-use.stderr
@@ -1,4 +1,4 @@
-error: unused return value of `anyhow::private::must_use` that must be used
+error: unused return value of `anyhow::__private::must_use` that must be used
  --> tests/ui/must-use.rs:8:9
   |
 8 |         anyhow!("it failed");
diff --git a/tests/ui/no-impl.stderr b/tests/ui/no-impl.stderr
index 02ab494..1ddf768 100644
--- a/tests/ui/no-impl.stderr
+++ b/tests/ui/no-impl.stderr
@@ -1,42 +1,31 @@
 error[E0599]: the method `anyhow_kind` exists for reference `&Error`, but its trait bounds were not satisfied
-   --> tests/ui/no-impl.rs:7:13
-    |
-4   | struct Error;
-    | -------------
-    | |
-    | doesn't satisfy `Error: Into<anyhow::Error>`
-    | doesn't satisfy `Error: anyhow::private::kind::TraitKind`
-    | doesn't satisfy `Error: std::fmt::Display`
+ --> tests/ui/no-impl.rs:7:13
+  |
+4 | struct Error;
+  | ------------
+  | |
+  | doesn't satisfy `Error: Into<anyhow::Error>`
+  | doesn't satisfy `Error: anyhow::kind::TraitKind`
+  | doesn't satisfy `Error: std::fmt::Display`
 ...
-7   |     let _ = anyhow!(Error);
-    |             ^^^^^^^^^^^^^^ method cannot be called on `&Error` due to unsatisfied trait bounds
-    |
-    = note: the following trait bounds were not satisfied:
-            `Error: Into<anyhow::Error>`
-            which is required by `Error: anyhow::private::kind::TraitKind`
-            `Error: std::fmt::Display`
-            which is required by `&Error: anyhow::private::kind::AdhocKind`
-            `&Error: Into<anyhow::Error>`
-            which is required by `&Error: anyhow::private::kind::TraitKind`
-note: the following traits must be implemented
-   --> $RUST/core/src/convert/mod.rs
-    |
-    | / pub trait Into<T>: Sized {
-    | |     /// Converts this type into the (usually inferred) input type.
-    | |     #[must_use]
-    | |     #[stable(feature = "rust1", since = "1.0.0")]
-    | |     fn into(self) -> T;
-    | | }
-    | |_^
-    |
-   ::: $RUST/core/src/fmt/mod.rs
-    |
-    | / pub trait Display {
-    | |     /// Formats the value using the given formatter.
-    | |     ///
-    | |     /// # Examples
-...   |
-    | |     fn fmt(&self, f: &mut Formatter<'_>) -> Result;
-    | | }
-    | |_^
-    = note: this error originates in the macro `anyhow` (in Nightly builds, run with -Z macro-backtrace for more info)
+7 |     let _ = anyhow!(Error);
+  |             ^^^^^^^^^^^^^^ method cannot be called on `&Error` due to unsatisfied trait bounds
+  |
+  = note: the following trait bounds were not satisfied:
+          `Error: Into<anyhow::Error>`
+          which is required by `Error: anyhow::kind::TraitKind`
+          `Error: std::fmt::Display`
+          which is required by `&Error: anyhow::kind::AdhocKind`
+          `&Error: Into<anyhow::Error>`
+          which is required by `&Error: anyhow::kind::TraitKind`
+note: the traits `Into` and `std::fmt::Display` must be implemented
+ --> $RUST/core/src/fmt/mod.rs
+  |
+  | pub trait Display {
+  | ^^^^^^^^^^^^^^^^^
+  |
+ ::: $RUST/core/src/convert/mod.rs
+  |
+  | pub trait Into<T>: Sized {
+  | ^^^^^^^^^^^^^^^^^^^^^^^^
+  = note: this error originates in the macro `anyhow` (in Nightly builds, run with -Z macro-backtrace for more info)
diff --git a/tests/ui/temporary-value.stderr b/tests/ui/temporary-value.stderr
index 4e4115f..dc27c49 100644
--- a/tests/ui/temporary-value.stderr
+++ b/tests/ui/temporary-value.stderr
@@ -4,6 +4,6 @@ error[E0716]: temporary value dropped while borrowed
 4 |     let _ = anyhow!(&String::new());
   |             ---------^^^^^^^^^^^^^-
   |             |        |
-  |             |        creates a temporary which is freed while still in use
+  |             |        creates a temporary value which is freed while still in use
   |             temporary value is freed at the end of this statement
   |             argument requires that borrow lasts for `'static`