Auto merge of #7776 - alexcrichton:anyhow, r=ehuss

Migrate from the `failure` crate to `anyhow`

The `anyhow` crate interoperates with the `std::error::Error` trait
rather than a custom `Fail` trait, and this is the general trend of
error handling in Rust as well.

Note that this is mostly mechanical (sed) and intended to get the test
suite passing. As usual there's still more idiomatic cleanup that can
happen, but that's left to later commits.

Author: bors

Cargo.toml

@@ -29,7 +29,7 @@ curl = { version = "0.4.23", features = ["http2"] }
 curl-sys = "0.4.22"
 env_logger = "0.7.0"
 pretty_env_logger = { version = "0.3", optional = true }
-failure = "0.1.5"
+anyhow = "1.0"
 filetime = "0.2"
 flate2 = { version = "1.0.3", features = ["zlib"] }
 fs2 = "0.4"
@@ -51,7 +51,7 @@ num_cpus = "1.0"
 opener = "0.4"
 percent-encoding = "2.0"
 remove_dir_all = "0.5.2"
-rustfix = "0.4.6"
+rustfix = "0.5.0"
 same-file = "1"
 semver = { version = "0.9.0", features = ["serde"] }
 serde = { version = "1.0.82", features = ["derive"] }

crates/cargo-test-support/src/lib.rs

@@ -916,11 +916,7 @@ impl Execs {
                 {
                     return self.match_output(out);
                 }
-                let mut s = format!("could not exec process {}: {}", process, e);
-                for cause in e.iter_causes() {
-                    s.push_str(&format!("\ncaused by: {}", cause));
-                }
-                Err(s)
+                Err(format!("could not exec process {}: {:?}", process, e))
             }
         }
     }

crates/crates-io/Cargo.toml

@@ -15,7 +15,7 @@ path = "lib.rs"
 
 [dependencies]
 curl = "0.4"
-failure = "0.1.1"
+anyhow = "1.0.0"
 percent-encoding = "2.0"
 serde = { version = "1.0", features = ['derive'] }
 serde_derive = "1.0"

crates/crates-io/lib.rs

@@ -7,15 +7,13 @@ use std::io::prelude::*;
 use std::io::Cursor;
 use std::time::Instant;
 
+use anyhow::{bail, Result};
 use curl::easy::{Easy, List};
-use failure::bail;
 use percent_encoding::{percent_encode, NON_ALPHANUMERIC};
 use serde::{Deserialize, Serialize};
 use serde_json;
 use url::Url;
 
-pub type Result<T> = std::result::Result<T, failure::Error>;
-
 pub struct Registry {
     /// The base URL for issuing API requests.
     host: String,

src/bin/cargo/commands/bench.rs

@@ -100,7 +100,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
     match err {
         None => Ok(()),
         Some(err) => Err(match err.exit.as_ref().and_then(|e| e.code()) {
-            Some(i) => CliError::new(failure::format_err!("bench failed"), i),
+            Some(i) => CliError::new(anyhow::format_err!("bench failed"), i),
             None => CliError::new(err.into(), 101),
         }),
     }

src/bin/cargo/commands/check.rs

@@ -60,7 +60,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         Some("test") => true,
         None => false,
         Some(profile) => {
-            let err = failure::format_err!(
+            let err = anyhow::format_err!(
                 "unknown profile: `{}`, only `test` is \
                  currently supported",
                 profile

src/bin/cargo/commands/clippy.rs

@@ -66,7 +66,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         args.compile_options(config, mode, Some(&ws), ProfileChecking::Checked)?;
 
     if !config.cli_unstable().unstable_options {
-        return Err(failure::format_err!(
+        return Err(anyhow::format_err!(
             "`clippy-preview` is unstable, pass `-Z unstable-options` to enable it"
         )
         .into());

src/bin/cargo/commands/fix.rs

@@ -120,7 +120,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         Some("test") => true,
         None => false,
         Some(profile) => {
-            let err = failure::format_err!(
+            let err = anyhow::format_err!(
                 "unknown profile: `{}`, only `test` is \
                  currently supported",
                 profile
@@ -143,7 +143,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         .filter(|_| use_clippy);
 
     if use_clippy && !config.cli_unstable().unstable_options {
-        return Err(failure::format_err!(
+        return Err(anyhow::format_err!(
             "`cargo fix --clippy` is unstable, pass `-Z unstable-options` to enable it"
         )
         .into());

src/bin/cargo/commands/locate_project.rs

@@ -21,7 +21,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
     let root = root
         .to_str()
         .ok_or_else(|| {
-            failure::format_err!(
+            anyhow::format_err!(
                 "your package path contains characters \
                  not representable in Unicode"
             )

src/bin/cargo/commands/rustc.rs

@@ -55,7 +55,7 @@ pub fn exec(config: &mut Config, args: &ArgMatches<'_>) -> CliResult {
         Some("bench") => CompileMode::Bench,
         Some("check") => CompileMode::Check { test: false },
         Some(mode) => {
-            let err = failure::format_err!(
+            let err = anyhow::format_err!(
                 "unknown profile: `{}`, use dev,
                                    test, or bench",
                 mode