Merge pull request #2829 from ehuss/log-to-tracing

Switch from log to tracing
2025-12-27 10:16:09 -05:00 · 2025-09-12 13:20:49 +00:00
parent 787882069e 3e673ce424
commit 8bb9a7ff42
46 changed files with 320 additions and 292 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -559,29 +559,6 @@ dependencies = [
 "serde_json",
 ]

-[[package]]
-name = "env_filter"
-version = "0.1.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "186e05a59d4c50738528153b83b0b0194d3a29507dfec16eccd4b342903397d0"
-dependencies = [
- "log",
- "regex",
-]
-
-[[package]]
-name = "env_logger"
-version = "0.11.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "13c863f0904021b108aa8b2f55046443e6b1ebde8fd4a15c399893aae4fa069f"
-dependencies = [
- "anstream",
- "anstyle",
- "env_filter",
- "jiff",
- "log",
-]
-
 [[package]]
 name = "equivalent"
 version = "1.0.2"
@@ -1132,30 +1109,6 @@ version = "1.0.15"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "4a5f13b858c8d314ee3e8f639011f7ccefe71f97f96e50151fb991f267928e2c"

-[[package]]
-name = "jiff"
-version = "0.2.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "be1f93b8b1eb69c77f24bbb0afdf66f54b632ee39af40ca21c4365a1d7347e49"
-dependencies = [
- "jiff-static",
- "log",
- "portable-atomic",
- "portable-atomic-util",
- "serde",
-]
-
-[[package]]
-name = "jiff-static"
-version = "0.2.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "03343451ff899767262ec32146f6d559dd759fdadf42ff0e227c7c48f72594b4"
-dependencies = [
- "proc-macro2",
- "quote",
- "syn 2.0.104",
-]
-
 [[package]]
 name = "js-sys"
 version = "0.3.77"
@@ -1186,6 +1139,12 @@ dependencies = [
 "libc",
 ]

+[[package]]
+name = "lazy_static"
+version = "1.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbd2bcb4c963f2ddae06a2efc7e9f3591312473c50c6685e1f298068316e66fe"
+
 [[package]]
 name = "libc"
 version = "0.2.174"
@@ -1291,6 +1250,15 @@ dependencies = [
 "syn 2.0.104",
 ]

+[[package]]
+name = "matchers"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d1525a2a28c7f4fa0fc98bb91ae755d1e2d1505079e05539e35bc876b5d65ae9"
+dependencies = [
+ "regex-automata",
+]
+
 [[package]]
 name = "matchit"
 version = "0.8.4"
@@ -1306,11 +1274,9 @@ dependencies = [
 "chrono",
 "clap",
 "clap_complete",
- "env_logger",
 "futures-util",
 "glob",
 "ignore",
- "log",
 "mdbook-core",
 "mdbook-driver",
 "mdbook-html",
@@ -1331,6 +1297,8 @@ dependencies = [
 "tokio",
 "toml",
 "tower-http",
+ "tracing",
+ "tracing-subscriber",
 "walkdir",
 ]

@@ -1339,12 +1307,12 @@ name = "mdbook-core"
 version = "0.5.0-alpha.1"
 dependencies = [
 "anyhow",
- "log",
 "regex",
 "serde",
 "serde_json",
 "tempfile",
 "toml",
+ "tracing",
 ]

 [[package]]
@@ -1353,7 +1321,6 @@ version = "0.5.0-alpha.1"
 dependencies = [
 "anyhow",
 "indexmap",
- "log",
 "mdbook-core",
 "mdbook-html",
 "mdbook-markdown",
@@ -1367,6 +1334,7 @@ dependencies = [
 "tempfile",
 "toml",
 "topological-sort",
+ "tracing",
 ]

 [[package]]
@@ -1379,7 +1347,6 @@ dependencies = [
 "font-awesome-as-a-crate",
 "handlebars",
 "hex",
- "log",
 "mdbook-core",
 "mdbook-markdown",
 "mdbook-renderer",
@@ -1391,15 +1358,16 @@ dependencies = [
 "sha2",
 "tempfile",
 "toml",
+ "tracing",
 ]

 [[package]]
 name = "mdbook-markdown"
 version = "0.5.0-alpha.1"
 dependencies = [
- "log",
 "pulldown-cmark",
 "regex",
+ "tracing",
 ]

 [[package]]
@@ -1437,11 +1405,11 @@ name = "mdbook-summary"
 version = "0.5.0-alpha.1"
 dependencies = [
 "anyhow",
- "log",
 "mdbook-core",
 "memchr",
 "pulldown-cmark",
 "serde",
+ "tracing",
 ]

 [[package]]
@@ -1544,6 +1512,15 @@ version = "2.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5e0826a989adedc2a244799e823aece04662b66609d96af8dff7ac6df9a8925d"

+[[package]]
+name = "nu-ansi-term"
+version = "0.50.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4a28e057d01f97e61255210fcff094d74ed0466038633e95017f5beb68e4399"
+dependencies = [
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "num-modular"
 version = "0.6.1"
@@ -1781,21 +1758,6 @@ version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"

-[[package]]
-name = "portable-atomic"
-version = "1.11.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f84267b20a16ea918e43c6a88433c2d54fa145c92a811b5b047ccbe153674483"
-
-[[package]]
-name = "portable-atomic-util"
-version = "0.2.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8a2f0d8d040d7848a709caf78912debcc3f33ee4b3cac47d73d1e1069e83507"
-dependencies = [
- "portable-atomic",
-]
-
 [[package]]
 name = "potential_utf"
 version = "0.1.2"
@@ -2126,6 +2088,15 @@ dependencies = [
 "digest",
 ]

+[[package]]
+name = "sharded-slab"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f40ca3c46823713e0d4209592e8d6e826aa57e928f09752619fc696c499637f6"
+dependencies = [
+ "lazy_static",
+]
+
 [[package]]
 name = "shlex"
 version = "1.3.0"
@@ -2333,6 +2304,15 @@ dependencies = [
 "syn 2.0.104",
 ]

+[[package]]
+name = "thread_local"
+version = "1.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f60246a4944f24f6e018aa17cdeffb7818b76356965d03b07d6a9886e8962185"
+dependencies = [
+ "cfg-if",
+]
+
 [[package]]
 name = "tinystr"
 version = "0.8.1"
@@ -2504,9 +2484,21 @@ checksum = "784e0ac535deb450455cbfa28a6f0df145ea1bb7ae51b821cf5e7927fdcfbdd0"
 dependencies = [
 "log",
 "pin-project-lite",
+ "tracing-attributes",
 "tracing-core",
 ]

+[[package]]
+name = "tracing-attributes"
+version = "0.1.30"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81383ab64e72a7a8b8e13130c49e3dab29def6d0c7d76a03087b3cf71c5c6903"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.104",
+]
+
 [[package]]
 name = "tracing-core"
 version = "0.1.34"
@@ -2514,6 +2506,36 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b9d12581f227e93f094d3af2ae690a574abb8a2b9b7a96e7cfe9647b2b617678"
 dependencies = [
 "once_cell",
+ "valuable",
+]
+
+[[package]]
+name = "tracing-log"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee855f1f400bd0e5c02d150ae5de3840039a3f54b025156404e34c23c03f47c3"
+dependencies = [
+ "log",
+ "once_cell",
+ "tracing-core",
+]
+
+[[package]]
+name = "tracing-subscriber"
+version = "0.3.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2054a14f5307d601f88daf0553e1cbf472acc4f2c51afab632431cdcd72124d5"
+dependencies = [
+ "matchers",
+ "nu-ansi-term",
+ "once_cell",
+ "regex-automata",
+ "sharded-slab",
+ "smallvec",
+ "thread_local",
+ "tracing",
+ "tracing-core",
+ "tracing-log",
 ]

 [[package]]
@@ -2598,6 +2620,12 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"

+[[package]]
+name = "valuable"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ba73ea9cf16a25df0c8caa16c51acb937d5712a8429db78a3ee29d5dcacd3a65"
+
 [[package]]
 name = "version_check"
 version = "0.9.5"
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -32,7 +32,6 @@ chrono = { version = "0.4.41", default-features = false, features = ["clock"] }
 clap = { version = "4.5.41", features = ["cargo", "wrap_help"] }
 clap_complete = "4.5.55"
 elasticlunr-rs = "3.0.2"
-env_logger = "0.11.8"
 font-awesome-as-a-crate = "0.3.0"
 futures-util = "0.3.31"
 glob = "0.3.3"
@@ -40,7 +39,6 @@ handlebars = "6.3.2"
 hex = "0.4.3"
 indexmap = "2.10.0"
 ignore = "0.4.23"
-log = "0.4.27"
 mdbook-core = { path = "crates/mdbook-core" }
 mdbook-driver = { path = "crates/mdbook-driver" }
 mdbook-html = { path = "crates/mdbook-html" }
@@ -68,6 +66,8 @@ tokio = "1.46.1"
 toml = "0.9.2"
 topological-sort = "0.2.2"
 tower-http = "0.6.6"
+tracing = "0.1.41"
+tracing-subscriber = { version = "0.3.20", features = ["env-filter"] }
 walkdir = "2.5.0"

 [package]
@@ -93,8 +93,6 @@ anyhow.workspace = true
 chrono.workspace = true
 clap.workspace = true
 clap_complete.workspace = true
-env_logger.workspace = true
-log.workspace = true
 mdbook-core.workspace = true
 mdbook-driver.workspace = true
 mdbook-html.workspace = true
@@ -104,6 +102,8 @@ mdbook-renderer.workspace = true
 mdbook-summary.workspace = true
 opener.workspace = true
 toml.workspace = true
+tracing.workspace = true
+tracing-subscriber.workspace = true

 # Watch feature
 ignore = { workspace = true, optional = true }
--- a/crates/mdbook-core/Cargo.toml
+++ b/crates/mdbook-core/Cargo.toml
@@ -9,11 +9,11 @@ rust-version.workspace = true

 [dependencies]
 anyhow.workspace = true
-log.workspace = true
 regex.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 toml.workspace = true
+tracing.workspace = true

 [dev-dependencies]
 tempfile.workspace = true
--- a/crates/mdbook-core/src/config.rs
+++ b/crates/mdbook-core/src/config.rs
@@ -46,7 +46,6 @@
 use crate::utils::TomlExt;
 use crate::utils::log_backtrace;
 use anyhow::{Context, Error, Result, bail};
-use log::{debug, trace};
 use serde::{Deserialize, Serialize};
 use std::collections::{BTreeMap, HashMap};
 use std::env;
@@ -56,6 +55,7 @@ use std::path::{Path, PathBuf};
 use std::str::FromStr;
 use toml::Value;
 use toml::value::Table;
+use tracing::{debug, trace};

 /// The overall configuration object for MDBook, essentially an in-memory
 /// representation of `book.toml`.
@@ -162,6 +162,10 @@ impl Config {
            env::vars().filter_map(|(key, value)| parse_env(&key).map(|index| (index, value)));

        for (key, value) in overrides {
+            if key == "log" {
+                // MDBOOK_LOG is used to control logging.
+                continue;
+            }
            trace!("{} => {}", key, value);
            let parsed_value = serde_json::from_str(&value)
                .unwrap_or_else(|_| serde_json::Value::String(value.to_string()));
--- a/crates/mdbook-core/src/utils/fs.rs
+++ b/crates/mdbook-core/src/utils/fs.rs
@@ -1,10 +1,10 @@
 //! Filesystem utilities and helpers.

 use anyhow::{Context, Result};
-use log::{debug, trace};
 use std::fs::{self, File};
 use std::io::Write;
 use std::path::{Component, Path, PathBuf};
+use tracing::{debug, trace};

 /// Naively replaces any path separator with a forward-slash '/'
 pub fn normalize_path(path: &str) -> String {
--- a/crates/mdbook-core/src/utils/mod.rs
+++ b/crates/mdbook-core/src/utils/mod.rs
@@ -1,11 +1,12 @@
 //! Various helpers and utilities.

 use anyhow::Error;
-use log::error;
 use regex::Regex;
 use std::borrow::Cow;
 use std::collections::HashMap;
+use std::fmt::Write;
 use std::sync::LazyLock;
+use tracing::error;

 pub mod fs;
 mod string;
@@ -79,11 +80,13 @@ pub fn unique_id_from_content(content: &str, id_counter: &mut HashMap<String, us

 /// Prints a "backtrace" of some `Error`.
 pub fn log_backtrace(e: &Error) {
-    error!("Error: {}", e);
+    let mut message = format!("{e}");

    for cause in e.chain().skip(1) {
-        error!("\tCaused By: {}", cause);
+        write!(message, "\n\tCaused by: {cause}").unwrap();
    }
+
+    error!("{message}");
 }

 /// Escape `<` and `>` for HTML.
--- a/crates/mdbook-driver/Cargo.toml
+++ b/crates/mdbook-driver/Cargo.toml
@@ -10,7 +10,6 @@ rust-version.workspace = true
 [dependencies]
 anyhow.workspace = true
 indexmap.workspace = true
-log.workspace = true
 mdbook-core.workspace = true
 mdbook-html.workspace = true
 mdbook-markdown.workspace = true
@@ -24,6 +23,7 @@ shlex.workspace = true
 tempfile.workspace = true
 toml.workspace = true
 topological-sort.workspace = true
+tracing.workspace = true

 [lints]
 workspace = true
--- a/crates/mdbook-driver/src/builtin_preprocessors/cmd.rs
+++ b/crates/mdbook-driver/src/builtin_preprocessors/cmd.rs
@@ -1,10 +1,10 @@
 use anyhow::{Context, Result, ensure};
-use log::{debug, trace, warn};
 use mdbook_core::book::Book;
 use mdbook_preprocessor::{Preprocessor, PreprocessorContext};
 use std::io::Write;
 use std::path::PathBuf;
 use std::process::{Child, Stdio};
+use tracing::{debug, trace, warn};

 /// A custom preprocessor which will shell out to a 3rd-party program.
 ///
--- a/crates/mdbook-driver/src/builtin_preprocessors/index.rs
+++ b/crates/mdbook-driver/src/builtin_preprocessors/index.rs
@@ -1,9 +1,9 @@
 use anyhow::Result;
-use log::warn;
 use mdbook_core::book::{Book, BookItem};
 use mdbook_preprocessor::{Preprocessor, PreprocessorContext};
 use regex::Regex;
 use std::{path::Path, sync::LazyLock};
+use tracing::warn;

 /// A preprocessor for converting file name `README.md` to `index.md` since
 /// `README.md` is the de facto index file in markdown-based documentation.
--- a/crates/mdbook-driver/src/builtin_preprocessors/links.rs
+++ b/crates/mdbook-driver/src/builtin_preprocessors/links.rs
@@ -1,5 +1,4 @@
 use anyhow::{Context, Result};
-use log::{error, warn};
 use mdbook_core::book::{Book, BookItem};
 use mdbook_core::utils::{
    take_anchored_lines, take_lines, take_rustdoc_include_anchored_lines,
@@ -11,6 +10,7 @@ use std::fs;
 use std::ops::{Bound, Range, RangeBounds, RangeFrom, RangeFull, RangeTo};
 use std::path::{Path, PathBuf};
 use std::sync::LazyLock;
+use tracing::{error, warn};

 const ESCAPE_CHAR: char = '\\';
 const MAX_LINK_NESTED_DEPTH: usize = 10;
--- a/crates/mdbook-driver/src/builtin_renderers/markdown_renderer.rs
+++ b/crates/mdbook-driver/src/builtin_renderers/markdown_renderer.rs
@@ -1,9 +1,9 @@
 use anyhow::{Context, Result};
-use log::trace;
 use mdbook_core::book::BookItem;
 use mdbook_core::utils;
 use mdbook_renderer::{RenderContext, Renderer};
 use std::fs;
+use tracing::trace;

 /// A renderer to output the Markdown after the preprocessors have run. Mostly useful
 /// when debugging preprocessors.
--- a/crates/mdbook-driver/src/builtin_renderers/mod.rs
+++ b/crates/mdbook-driver/src/builtin_renderers/mod.rs
@@ -3,10 +3,10 @@
 //! The HTML renderer can be found in the [`mdbook_html`] crate.

 use anyhow::{Context, Result, bail};
-use log::{error, info, trace, warn};
 use mdbook_renderer::{RenderContext, Renderer};
 use std::fs;
 use std::process::Stdio;
+use tracing::{error, info, trace, warn};

 pub use self::markdown_renderer::MarkdownRenderer;

@@ -30,7 +30,7 @@ mod markdown_renderer;
 /// whatever it wants, to avoid spamming users it is recommended to avoid
 /// unnecessary output.
 ///
-/// To help choose the appropriate output level, the `RUST_LOG` environment
+/// To help choose the appropriate output level, the `MDBOOK_LOG` environment
 /// variable will be passed through to the subprocess, if set.
 ///
 /// If the subprocess wishes to indicate that rendering failed, it should exit
--- a/crates/mdbook-driver/src/init.rs
+++ b/crates/mdbook-driver/src/init.rs
@@ -6,10 +6,10 @@ use std::path::PathBuf;

 use super::MDBook;
 use anyhow::{Context, Result};
-use log::{debug, error, info, trace};
 use mdbook_core::config::Config;
 use mdbook_core::utils::fs::write_file;
 use mdbook_html::theme;
+use tracing::{debug, error, info, trace};

 /// A helper for setting up a new book and its directory structure.
 #[derive(Debug, Clone, PartialEq)]
--- a/crates/mdbook-driver/src/lib.rs
+++ b/crates/mdbook-driver/src/lib.rs
@@ -65,12 +65,12 @@ mod load;
 mod mdbook;

 use anyhow::{Context, Result, bail};
-use log::{error, warn};
 pub use mdbook::MDBook;
 pub use mdbook_core::{book, config, errors};
 use shlex::Shlex;
 use std::path::{Path, PathBuf};
 use std::process::Command;
+use tracing::{error, warn};

 /// Creates a [`Command`] for command renderers and preprocessors.
 fn compose_command(cmd: &str, root: &Path) -> Result<Command> {
--- a/crates/mdbook-driver/src/load.rs
+++ b/crates/mdbook-driver/src/load.rs
@@ -1,5 +1,4 @@
 use anyhow::{Context, Result};
-use log::debug;
 use mdbook_core::book::{Book, BookItem, Chapter};
 use mdbook_core::config::BuildConfig;
 use mdbook_core::utils::bracket_escape;
@@ -7,6 +6,7 @@ use mdbook_summary::{Link, Summary, SummaryItem, parse_summary};
 use std::fs::{self, File};
 use std::io::{Read, Write};
 use std::path::Path;
+use tracing::debug;

 /// Load a book into memory from its `src/` directory.
 pub(crate) fn load_book<P: AsRef<Path>>(src_dir: P, cfg: &BuildConfig) -> Result<Book> {
--- a/crates/mdbook-driver/src/mdbook.rs
+++ b/crates/mdbook-driver/src/mdbook.rs
@@ -6,7 +6,6 @@ use crate::init::BookBuilder;
 use crate::load::{load_book, load_book_from_disk};
 use anyhow::{Context, Error, Result, bail};
 use indexmap::IndexMap;
-use log::{debug, error, info, log_enabled, trace, warn};
 use mdbook_core::book::{Book, BookItem, BookItems};
 use mdbook_core::config::{Config, RustEdition};
 use mdbook_core::utils;
@@ -21,6 +20,7 @@ use std::path::{Path, PathBuf};
 use std::process::Command;
 use tempfile::Builder as TempFileBuilder;
 use topological_sort::TopologicalSort;
+use tracing::{debug, error, info, trace, warn};

 #[cfg(test)]
 mod tests;
@@ -58,7 +58,7 @@ impl MDBook {

        config.update_from_env();

-        if log_enabled!(log::Level::Trace) {
+        if tracing::enabled!(tracing::Level::TRACE) {
            for line in format!("Config: {config:#?}").lines() {
                trace!("{}", line);
            }
--- a/crates/mdbook-html/Cargo.toml
+++ b/crates/mdbook-html/Cargo.toml
@@ -14,7 +14,6 @@ elasticlunr-rs = { workspace = true, optional = true }
 font-awesome-as-a-crate.workspace = true
 handlebars.workspace = true
 hex.workspace = true
-log.workspace = true
 mdbook-core.workspace = true
 mdbook-markdown.workspace = true
 mdbook-renderer.workspace = true
@@ -23,6 +22,7 @@ regex.workspace = true
 serde.workspace = true
 serde_json.workspace = true
 sha2.workspace = true
+tracing.workspace = true

 [dev-dependencies]
 pretty_assertions.workspace = true
--- a/crates/mdbook-html/src/html_handlebars/hbs_renderer.rs
+++ b/crates/mdbook-html/src/html_handlebars/hbs_renderer.rs
@@ -3,7 +3,6 @@ use super::static_files::StaticFiles;
 use crate::theme::Theme;
 use anyhow::{Context, Result, bail};
 use handlebars::Handlebars;
-use log::{debug, info, trace, warn};
 use mdbook_core::book::{Book, BookItem, Chapter};
 use mdbook_core::config::{BookConfig, Code, Config, HtmlConfig, Playground, RustEdition};
 use mdbook_core::utils;
@@ -18,6 +17,8 @@ use std::collections::HashMap;
 use std::fs::{self, File};
 use std::path::{Path, PathBuf};
 use std::sync::LazyLock;
+use tracing::error;
+use tracing::{debug, info, trace, warn};

 /// The HTML renderer for mdBook.
 #[derive(Default)]
@@ -286,7 +287,7 @@ impl HtmlHandlebars {
            return Ok(());
        }

-        log::debug!("Emitting redirects");
+        debug!("Emitting redirects");
        let redirects = combine_fragment_redirects(redirects);

        for (original, (dest, fragment_map)) in redirects {
@@ -306,7 +307,7 @@ impl HtmlHandlebars {
                     destination."
                );
            }
-            log::debug!("Redirecting \"{}\" → \"{}\"", original, dest);
+            debug!("Redirecting \"{}\" → \"{}\"", original, dest);
            self.emit_redirect(handlebars, &filename, &dest, &fragment_map)?;
        }

@@ -1034,7 +1035,7 @@ fn combine_fragment_redirects(redirects: &HashMap<String, String>) -> CombinedRe
        if let Some((source_path, source_fragment)) = original.rsplit_once('#') {
            let e = combined.entry(source_path.to_string()).or_default();
            if let Some(old) = e.1.insert(format!("#{source_fragment}"), new.clone()) {
-                log::error!(
+                error!(
                    "internal error: found duplicate fragment redirect \
                     {old} for {source_path}#{source_fragment}"
                );
--- a/crates/mdbook-html/src/html_handlebars/helpers/fontawesome.rs
+++ b/crates/mdbook-html/src/html_handlebars/helpers/fontawesome.rs
@@ -2,8 +2,8 @@ use font_awesome_as_a_crate as fa;
 use handlebars::{
    Context, Handlebars, Helper, Output, RenderContext, RenderError, RenderErrorReason,
 };
-use log::trace;
 use std::str::FromStr;
+use tracing::trace;

 pub(crate) fn fa_helper(
    h: &Helper<'_>,
--- a/crates/mdbook-html/src/html_handlebars/search.rs
+++ b/crates/mdbook-html/src/html_handlebars/search.rs
@@ -2,7 +2,6 @@ use super::static_files::StaticFiles;
 use crate::theme::searcher;
 use anyhow::{Context, Result, bail};
 use elasticlunr::{Index, IndexBuilder};
-use log::{debug, warn};
 use mdbook_core::book::{Book, BookItem, Chapter};
 use mdbook_core::config::{Search, SearchChapterSettings};
 use mdbook_core::utils;
@@ -14,6 +13,7 @@ use std::borrow::Cow;
 use std::collections::{HashMap, HashSet};
 use std::path::{Path, PathBuf};
 use std::sync::LazyLock;
+use tracing::{debug, warn};

 const MAX_WORD_LENGTH_TO_INDEX: usize = 80;

--- a/crates/mdbook-html/src/html_handlebars/static_files.rs
+++ b/crates/mdbook-html/src/html_handlebars/static_files.rs
@@ -3,7 +3,6 @@
 use super::helpers::resources::ResourceHelper;
 use crate::theme::{self, Theme, playground_editor};
 use anyhow::{Context, Result};
-use log::debug;
 use mdbook_core::config::HtmlConfig;
 use mdbook_core::utils;
 use std::borrow::Cow;
@@ -11,6 +10,7 @@ use std::collections::HashMap;
 use std::fs::{self, File};
 use std::path::{Path, PathBuf};
 use std::sync::LazyLock;
+use tracing::debug;

 /// Map static files to their final names and contents.
 ///
--- a/crates/mdbook-html/src/theme/mod.rs
+++ b/crates/mdbook-html/src/theme/mod.rs
@@ -1,10 +1,10 @@
 #![allow(missing_docs)]

 use anyhow::Result;
-use log::warn;
 use std::fs::File;
 use std::io::Read;
 use std::path::{Path, PathBuf};
+use tracing::{info, warn};

 pub mod fonts;
 pub mod playground_editor;
@@ -133,7 +133,7 @@ impl Theme {
                            if entry.file_name() == "fonts.css" {
                                None
                            } else if entry.file_type().ok()?.is_dir() {
-                                log::info!("skipping font directory {:?}", entry.path());
+                                info!("skipping font directory {:?}", entry.path());
                                None
                            } else {
                                Some(entry.path())
--- a/crates/mdbook-markdown/Cargo.toml
+++ b/crates/mdbook-markdown/Cargo.toml
@@ -8,9 +8,9 @@ repository.workspace = true
 rust-version.workspace = true

 [dependencies]
-log.workspace = true
 pulldown-cmark.workspace = true
 regex.workspace = true
+tracing.workspace = true

 [lints]
 workspace = true
--- a/crates/mdbook-markdown/src/lib.rs
+++ b/crates/mdbook-markdown/src/lib.rs
@@ -15,6 +15,7 @@ use std::collections::HashMap;
 use std::fmt::Write;
 use std::path::Path;
 use std::sync::LazyLock;
+use tracing::warn;

 #[doc(inline)]
 pub use pulldown_cmark;
@@ -126,7 +127,7 @@ pub fn render_markdown(text: &str, options: &HtmlRenderOptions<'_>) -> String {
                Event::Start(Tag::FootnoteDefinition(name)) => {
                    prev_was_footnote = false;
                    if !in_footnote.is_empty() {
-                        log::warn!(
+                        warn!(
                            "internal bug: nested footnote not expected in {:?}",
                            options.path
                        );
@@ -139,7 +140,7 @@ pub fn render_markdown(text: &str, options: &HtmlRenderOptions<'_>) -> String {
                    let name = std::mem::take(&mut in_footnote_name);

                    if footnote_defs.contains_key(&name) {
-                        log::warn!(
+                        warn!(
                            "footnote `{name}` in {} defined multiple times - \
                             not updating to new definition",
                            options.path.display()
@@ -212,7 +213,7 @@ fn add_footnote_defs(
    // Remove unused.
    defs.retain(|(name, _)| {
        if !numbers.contains_key(name) {
-            log::warn!(
+            warn!(
                "footnote `{name}` in `{}` is defined but not referenced",
                options.path.display()
            );
--- a/crates/mdbook-summary/Cargo.toml
+++ b/crates/mdbook-summary/Cargo.toml
@@ -9,11 +9,11 @@ rust-version.workspace = true

 [dependencies]
 anyhow.workspace = true
-log.workspace = true
 mdbook-core.workspace = true
 memchr.workspace = true
 pulldown-cmark.workspace = true
 serde.workspace = true
+tracing.workspace = true

 [lints]
 workspace = true
--- a/crates/mdbook-summary/src/lib.rs
+++ b/crates/mdbook-summary/src/lib.rs
@@ -5,7 +5,6 @@
 //! file structure for [mdBook](https://rust-lang.github.io/mdBook/).

 use anyhow::{Context, Error, Result, bail};
-use log::{debug, trace, warn};
 pub use mdbook_core::book::SectionNumber;
 use memchr::Memchr;
 use pulldown_cmark::{DefaultBrokenLinkCallback, Event, HeadingLevel, Tag, TagEnd};
@@ -13,6 +12,7 @@ use serde::{Deserialize, Serialize};
 use std::collections::HashSet;
 use std::fmt::Display;
 use std::path::{Path, PathBuf};
+use tracing::{debug, trace, warn};

 /// Parse the text from a `SUMMARY.md` file into a sort of "recipe" to be
 /// used when loading a book from disk.
--- a/guide/src/for_developers/backends.md
+++ b/guide/src/for_developers/backends.md
@@ -317,7 +317,7 @@ the "rule of silence" and only generate output when necessary (e.g. an error in
 generation or a warning).

 All environment variables are passed through to the backend, allowing you to use
-the usual `RUST_LOG` to control logging verbosity.
+the usual `MDBOOK_LOG` to control logging verbosity.

 ## Wrapping up

--- a/src/cmd/build.rs
+++ b/src/cmd/build.rs
@@ -2,6 +2,7 @@ use super::command_prelude::*;
 use crate::{get_book_dir, open};
 use anyhow::Result;
 use mdbook_driver::MDBook;
+use tracing::error;

 // Create clap subcommand arguments
 pub fn make_subcommand() -> Command {
--- a/src/cmd/init.rs
+++ b/src/cmd/init.rs
@@ -6,6 +6,7 @@ use mdbook_driver::MDBook;
 use std::io;
 use std::io::Write;
 use std::process::Command;
+use tracing::debug;

 // Create clap subcommand arguments
 pub fn make_subcommand() -> ClapCommand {
--- a/src/cmd/serve.rs
+++ b/src/cmd/serve.rs
@@ -15,6 +15,7 @@ use std::net::{SocketAddr, ToSocketAddrs};
 use std::path::PathBuf;
 use tokio::sync::broadcast;
 use tower_http::services::{ServeDir, ServeFile};
+use tracing::{error, info, trace};

 /// The HTTP endpoint for the websocket used to trigger reloads when a file changes.
 const LIVE_RELOAD_ENDPOINT: &str = "__livereload";
--- a/src/cmd/watch.rs
+++ b/src/cmd/watch.rs
@@ -3,6 +3,7 @@ use crate::{get_book_dir, open};
 use anyhow::Result;
 use mdbook_driver::MDBook;
 use std::path::{Path, PathBuf};
+use tracing::error;

 mod native;
 mod poller;
--- a/src/cmd/watch/native.rs
+++ b/src/cmd/watch/native.rs
@@ -6,6 +6,7 @@ use std::path::{Path, PathBuf};
 use std::sync::mpsc::channel;
 use std::thread::sleep;
 use std::time::Duration;
+use tracing::{error, info, warn};

 pub fn rebuild_on_change(
    book_dir: &Path,
@@ -71,7 +72,7 @@ pub fn rebuild_on_change(
            .filter_map(|event| match event {
                Ok(events) => Some(events),
                Err(error) => {
-                    log::warn!("error while watching for changes: {error}");
+                    warn!("error while watching for changes: {error}");
                    None
                }
            })
--- a/src/cmd/watch/poller.rs
+++ b/src/cmd/watch/poller.rs
@@ -11,6 +11,7 @@ use std::collections::HashMap;
 use std::fs::FileType;
 use std::path::{Path, PathBuf};
 use std::time::{Duration, Instant, SystemTime};
+use tracing::{debug, error, info, trace, warn};
 use walkdir::WalkDir;

 /// Calls the closure when a book source file is changed, blocking indefinitely.
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,20 +4,15 @@

 #[macro_use]
 extern crate clap;
-#[macro_use]
-extern crate log;

 use anyhow::anyhow;
-use chrono::Local;
 use clap::{Arg, ArgMatches, Command};
 use clap_complete::Shell;
-use env_logger::Builder;
-use log::LevelFilter;
 use mdbook_core::utils;
 use std::env;
 use std::ffi::OsStr;
-use std::io::Write;
 use std::path::PathBuf;
+use tracing::{error, info};

 mod cmd;

@@ -99,29 +94,36 @@ fn create_clap_command() -> Command {
 }

 fn init_logger() {
-    let mut builder = Builder::new();
+    let filter = tracing_subscriber::EnvFilter::builder()
+        .with_env_var("MDBOOK_LOG")
+        .with_default_directive(tracing_subscriber::filter::LevelFilter::INFO.into())
+        .from_env_lossy();
+    let log_env = std::env::var("MDBOOK_LOG");
+    // Silence some particularly noisy dependencies unless the user
+    // specifically asks for them.
+    let silence_unless_specified = |filter: tracing_subscriber::EnvFilter, target| {
+        if !log_env.as_ref().map_or(false, |s| {
+            s.split(',').any(|directive| directive.starts_with(target))
+        }) {
+            filter.add_directive(format!("{target}=warn").parse().unwrap())
+        } else {
+            filter
+        }
+    };
+    let filter = silence_unless_specified(filter, "handlebars");
+    let filter = silence_unless_specified(filter, "html5ever");

-    builder.format(|formatter, record| {
-        writeln!(
-            formatter,
-            "{} [{}] ({}): {}",
-            Local::now().format("%Y-%m-%d %H:%M:%S"),
-            record.level(),
-            record.target(),
-            record.args()
-        )
-    });
+    // Don't show the target by default, since it generally isn't useful
+    // unless you are overriding the level.
+    let with_target = log_env.is_ok();

-    if let Ok(var) = env::var("RUST_LOG") {
-        builder.parse_filters(&var);
-    } else {
-        // if no RUST_LOG provided, default to logging at the Info level
-        builder.filter(None, LevelFilter::Info);
-        // Filter extraneous html5ever not-implemented messages
-        builder.filter(Some("html5ever"), LevelFilter::Error);
-    }
-
-    builder.init();
+    tracing_subscriber::fmt()
+        .without_time()
+        .with_ansi(std::io::IsTerminal::is_terminal(&std::io::stderr()))
+        .with_writer(std::io::stderr)
+        .with_env_filter(filter)
+        .with_target(with_target)
+        .init();
 }

 fn get_book_dir(args: &ArgMatches) -> PathBuf {
--- a/tests/testsuite/book_test.rs
+++ b/tests/testsuite/book_test.rs
@@ -360,7 +360,7 @@ impl BookCommand {

    /// Use this to debug a command.
    ///
-    /// Pass the value that you would normally pass to `RUST_LOG`, and this
+    /// Pass the value that you would normally pass to `MDBOOK_LOG`, and this
    /// will enable logging, print the command that runs and its output.
    ///
    /// This will fail if you use it in CI.
@@ -378,7 +378,7 @@ impl BookCommand {
        let mut cmd = Command::new(env!("CARGO_BIN_EXE_mdbook"));
        cmd.current_dir(&self.dir)
            .args(&self.args)
-            .env_remove("RUST_LOG")
+            .env_remove("MDBOOK_LOG")
            // Don't read the system git config which is out of our control.
            .env("GIT_CONFIG_NOSYSTEM", "1")
            .env("GIT_CONFIG_GLOBAL", &self.dir)
@@ -389,7 +389,7 @@ impl BookCommand {
            .env_remove("GIT_COMMITTER_NAME");

        if let Some(debug) = &self.debug {
-            cmd.env("RUST_LOG", debug);
+            cmd.env("MDBOOK_LOG", debug);
        }

        for (k, v) in &self.env {
@@ -479,23 +479,9 @@ static LITERAL_REDACTIONS: &[(&str, &str)] = &[
    ("[EXE]", std::env::consts::EXE_SUFFIX),
 ];

-/// This makes it easier to write regex replacements that are guaranteed to only
-/// get compiled once
-macro_rules! regex {
-    ($re:literal $(,)?) => {{
-        static RE: std::sync::OnceLock<regex::Regex> = std::sync::OnceLock::new();
-        RE.get_or_init(|| regex::Regex::new($re).unwrap())
-    }};
-}
-
 fn assert(root: &Path) -> snapbox::Assert {
    let mut subs = snapbox::Redactions::new();
    subs.insert("[ROOT]", root.to_path_buf()).unwrap();
-    subs.insert(
-        "[TIMESTAMP]",
-        regex!(r"(?m)(?<redacted>20\d\d-\d{2}-\d{2} \d{2}:\d{2}:\d{2})"),
-    )
-    .unwrap();
    subs.insert("[VERSION]", mdbook_core::MDBOOK_VERSION)
        .unwrap();

--- a/tests/testsuite/build.rs
+++ b/tests/testsuite/build.rs
@@ -10,9 +10,9 @@ use crate::prelude::*;
 fn basic_build() {
    BookTest::from_dir("build/basic_build").run("build", |cmd| {
        cmd.expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
    });
@@ -24,8 +24,8 @@ fn basic_build() {
 fn failure_on_missing_file() {
    BookTest::from_dir("build/missing_file").run("build", |cmd| {
        cmd.expect_failure().expect_stderr(str![[r#"
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Chapter file not found, ./chapter_1.md
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: [NOT_FOUND]
+ERROR Chapter file not found, ./chapter_1.md
+[TAB]Caused by: [NOT_FOUND]

 "#]]);
    });
@@ -46,10 +46,10 @@ fn create_missing() {
 fn no_reserved_filename() {
    BookTest::from_dir("build/no_reserved_filename").run("build", |cmd| {
        cmd.expect_failure().expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: print.md is reserved for internal use
+ INFO Book building has started
+ INFO Running the html backend
+ERROR Rendering failed
+[TAB]Caused by: print.md is reserved for internal use

 "#]]);
    });
@@ -77,9 +77,9 @@ fn dest_dir_relative_path() {
        cmd.args(&["--dest-dir", "foo", ".."])
            .current_dir(&current_dir)
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/work/foo`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/work/foo`

 "#]]);
    });
--- a/tests/testsuite/config.rs
+++ b/tests/testsuite/config.rs
@@ -120,8 +120,8 @@ fn bad_config_top_level() {
            cmd.expect_failure()
                .expect_stdout(str![[""]])
                .expect_stderr(str![[r#"
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Invalid configuration file
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: TOML parse error at line 1, column 1
+ERROR Invalid configuration file
+[TAB]Caused by: TOML parse error at line 1, column 1
  |
 1 | foo = 123
  | ^^^
@@ -145,8 +145,8 @@ fn bad_config_top_level_table() {
            cmd.expect_failure()
                .expect_stdout(str![[""]])
                .expect_stderr(str![[r#"
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Invalid configuration file
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: TOML parse error at line 1, column 2
+ERROR Invalid configuration file
+[TAB]Caused by: TOML parse error at line 1, column 2
  |
 1 | [other]
  |  ^^^^^
@@ -171,8 +171,8 @@ fn bad_config_in_book_table() {
            cmd.expect_failure()
                .expect_stdout(str![[""]])
                .expect_stderr(str![[r#"
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Invalid configuration file
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: TOML parse error at line 3, column 1
+ERROR Invalid configuration file
+[TAB]Caused by: TOML parse error at line 3, column 1
  |
 3 | foo = 123
  | ^^^
@@ -196,8 +196,8 @@ fn bad_config_in_rust_table() {
            cmd.expect_failure()
                .expect_stdout(str![[""]])
                .expect_stderr(str![[r#"
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Invalid configuration file
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: TOML parse error at line 2, column 1
+ERROR Invalid configuration file
+[TAB]Caused by: TOML parse error at line 2, column 1
  |
 2 | title = "bad-config"
  | ^^^^^
--- a/tests/testsuite/includes.rs
+++ b/tests/testsuite/includes.rs
@@ -45,10 +45,10 @@ fn recursive_include() {
    BookTest::from_dir("includes/all_includes")
        .run("build", |cmd| {
            cmd.expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [ERROR] (mdbook_driver::builtin_preprocessors::links): Stack depth exceeded in recursive.md. Check for cyclic includes
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ERROR Stack depth exceeded in recursive.md. Check for cyclic includes
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
        })
--- a/tests/testsuite/init.rs
+++ b/tests/testsuite/init.rs
@@ -19,7 +19,7 @@ All done, no errors...

 "#]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::init): Creating a new book with stub content
+ INFO Creating a new book with stub content

 "#]]);
    })
@@ -84,7 +84,7 @@ All done, no errors...

 "#]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::init): Creating a new book with stub content
+ INFO Creating a new book with stub content

 "#]]);
    })
@@ -115,7 +115,7 @@ All done, no errors...

 "#]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::init): Creating a new book with stub content
+ INFO Creating a new book with stub content

 "#]])
            .args(&["--title", "Example title"]);
--- a/tests/testsuite/markdown.rs
+++ b/tests/testsuite/markdown.rs
@@ -20,13 +20,13 @@ fn footnotes() {
    BookTest::from_dir("markdown/footnotes")
        .run("build", |cmd| {
            cmd.expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [WARN] (mdbook_markdown): footnote `multiple-definitions` in footnotes.md defined multiple times - not updating to new definition
-[TIMESTAMP] [WARN] (mdbook_markdown): footnote `unused` in `footnotes.md` is defined but not referenced
-[TIMESTAMP] [WARN] (mdbook_markdown): footnote `multiple-definitions` in footnotes.md defined multiple times - not updating to new definition
-[TIMESTAMP] [WARN] (mdbook_markdown): footnote `unused` in `footnotes.md` is defined but not referenced
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ WARN footnote `multiple-definitions` in footnotes.md defined multiple times - not updating to new definition
+ WARN footnote `unused` in `footnotes.md` is defined but not referenced
+ WARN footnote `multiple-definitions` in footnotes.md defined multiple times - not updating to new definition
+ WARN footnote `unused` in `footnotes.md` is defined but not referenced
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
        })
--- a/tests/testsuite/preprocessor.rs
+++ b/tests/testsuite/preprocessor.rs
@@ -49,9 +49,9 @@ fn runs_preprocessors() {
 fn nop_preprocessor() {
    BookTest::from_dir("preprocessor/nop_preprocessor").run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
    });
@@ -60,17 +60,16 @@ fn nop_preprocessor() {
 // Failing preprocessor generates an error.
 #[test]
 fn failing_preprocessor() {
-    BookTest::from_dir("preprocessor/failing_preprocessor")
-        .run("build", |cmd| {
-            cmd.expect_failure()
-                .expect_stdout(str![[""]])
-                .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
+    BookTest::from_dir("preprocessor/failing_preprocessor").run("build", |cmd| {
+        cmd.expect_failure()
+            .expect_stdout(str![[""]])
+            .expect_stderr(str![[r#"
+ INFO Book building has started
 Boom!!1!
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: The "nop-preprocessor" preprocessor exited unsuccessfully with [EXIT_STATUS]: 1 status
+ERROR The "nop-preprocessor" preprocessor exited unsuccessfully with [EXIT_STATUS]: 1 status

 "#]]);
-        });
+    });
 }

 fn example() -> CmdPreprocessor {
@@ -128,9 +127,9 @@ fn relative_command_path() {
    )
    .run("build", |cmd| {
        cmd.expect_stdout(str![""]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
    })
@@ -143,9 +142,9 @@ fn relative_command_path() {
        cmd.current_dir(cmd.dir.join("src"))
            .expect_stdout(str![""])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/src/../book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/src/../book`

 "#]]);
    })
@@ -160,10 +159,10 @@ fn missing_preprocessor() {
        cmd.expect_failure()
            .expect_stdout(str![[""]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [ERROR] (mdbook_driver): The command `trduyvbhijnorgevfuhn` wasn't found, is the `missing` preprocessor installed? If you want to ignore this error when the `missing` preprocessor is not installed, set `optional = true` in the `[preprocessor.missing]` section of the book.toml configuration file.
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Unable to run the preprocessor `missing`
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: [NOT_FOUND]
+ INFO Book building has started
+ERROR The command `trduyvbhijnorgevfuhn` wasn't found, is the `missing` preprocessor installed? If you want to ignore this error when the `missing` preprocessor is not installed, set `optional = true` in the `[preprocessor.missing]` section of the book.toml configuration file.
+ERROR Unable to run the preprocessor `missing`
+[TAB]Caused by: [NOT_FOUND]

 "#]]);
    });
@@ -174,10 +173,10 @@ fn missing_preprocessor() {
 fn missing_optional_not_fatal() {
    BookTest::from_dir("preprocessor/missing_optional_not_fatal").run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [WARN] (mdbook_driver): The command `trduyvbhijnorgevfuhn` for preprocessor `missing` was not found, but is marked as optional.
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ WARN The command `trduyvbhijnorgevfuhn` for preprocessor `missing` was not found, but is marked as optional.
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
    });
@@ -239,14 +238,14 @@ fn extension_compatibility() {
    // that the built book is identical with the preprocessor enabled.
    test.run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [WARN] (mdbook_driver): The command `./my-preprocessor` for preprocessor `my-preprocessor` was not found, but is marked as optional.
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book/html`
-[TIMESTAMP] [WARN] (mdbook_driver): The command `./my-preprocessor` for preprocessor `my-preprocessor` was not found, but is marked as optional.
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the my-renderer backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "my-renderer" renderer
-[TIMESTAMP] [WARN] (mdbook_driver): The command `./my-renderer` for backend `my-renderer` was not found, but is marked as optional.
+ INFO Book building has started
+ WARN The command `./my-preprocessor` for preprocessor `my-preprocessor` was not found, but is marked as optional.
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book/html`
+ WARN The command `./my-preprocessor` for preprocessor `my-preprocessor` was not found, but is marked as optional.
+ INFO Running the my-renderer backend
+ INFO Invoking the "my-renderer" renderer
+ WARN The command `./my-renderer` for backend `my-renderer` was not found, but is marked as optional.

 "#]]);
    });
@@ -441,11 +440,11 @@ fn extension_compatibility() {
    )
    .run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book/html`
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the my-renderer backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "my-renderer" renderer
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book/html`
+ INFO Running the my-renderer backend
+ INFO Invoking the "my-renderer" renderer

 "#]]);
    })
--- a/tests/testsuite/redirects.rs
+++ b/tests/testsuite/redirects.rs
@@ -22,11 +22,11 @@ fn redirects_are_emitted_correctly() {
 fn redirect_removed_with_fragments_only() {
    BookTest::from_dir("redirects/redirect_removed_with_fragments_only").run("build", |cmd| {
        cmd.expect_failure().expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: Unable to emit redirects
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: redirect entry for `old-file.html` only has source paths with `#` fragments
+ INFO Book building has started
+ INFO Running the html backend
+ERROR Rendering failed
+[TAB]Caused by: Unable to emit redirects
+[TAB]Caused by: redirect entry for `old-file.html` only has source paths with `#` fragments
 There must be an entry without the `#` fragment to determine the default destination.

 "#]]);
@@ -38,10 +38,10 @@ There must be an entry without the `#` fragment to determine the default destina
 fn redirect_existing_page() {
    BookTest::from_dir("redirects/redirect_existing_page").run("build", |cmd| {
        cmd.expect_failure().expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: redirect found for existing chapter at `/chapter_1.html`
+ INFO Book building has started
+ INFO Running the html backend
+ERROR Rendering failed
+[TAB]Caused by: redirect found for existing chapter at `/chapter_1.html`
 Either delete the redirect or remove the chapter.

 "#]]);
--- a/tests/testsuite/renderer.rs
+++ b/tests/testsuite/renderer.rs
@@ -64,12 +64,12 @@ fn failing_command() {
            cmd.expect_failure()
                .expect_stdout(str![[""]])
                .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the failing backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "failing" renderer
-[TIMESTAMP] [ERROR] (mdbook_driver::builtin_renderers): Renderer exited with non-zero return code.
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: The "failing" renderer failed
+ INFO Book building has started
+ INFO Running the failing backend
+ INFO Invoking the "failing" renderer
+ERROR Renderer exited with non-zero return code.
+ERROR Rendering failed
+[TAB]Caused by: The "failing" renderer failed

 "#]]);
        });
@@ -82,13 +82,13 @@ fn missing_renderer() {
        cmd.expect_failure()
            .expect_stdout(str![[""]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the missing backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "missing" renderer
-[TIMESTAMP] [ERROR] (mdbook_driver): The command `trduyvbhijnorgevfuhn` wasn't found, is the `missing` backend installed? If you want to ignore this error when the `missing` backend is not installed, set `optional = true` in the `[output.missing]` section of the book.toml configuration file.
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: Unable to run the backend `missing`
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: [NOT_FOUND]
+ INFO Book building has started
+ INFO Running the missing backend
+ INFO Invoking the "missing" renderer
+ERROR The command `trduyvbhijnorgevfuhn` wasn't found, is the `missing` backend installed? If you want to ignore this error when the `missing` backend is not installed, set `optional = true` in the `[output.missing]` section of the book.toml configuration file.
+ERROR Rendering failed
+[TAB]Caused by: Unable to run the backend `missing`
+[TAB]Caused by: [NOT_FOUND]

 "#]]);
    });
@@ -99,10 +99,10 @@ fn missing_renderer() {
 fn missing_optional_not_fatal() {
    BookTest::from_dir("renderer/missing_optional_not_fatal").run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the missing backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "missing" renderer
-[TIMESTAMP] [WARN] (mdbook_driver): The command `trduyvbhijnorgevfuhn` for backend `missing` was not found, but is marked as optional.
+ INFO Book building has started
+ INFO Running the missing backend
+ INFO Invoking the "missing" renderer
+ WARN The command `trduyvbhijnorgevfuhn` for backend `missing` was not found, but is marked as optional.

 "#]]);
    });
@@ -131,9 +131,9 @@ Hello World!

 "#]])
                .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the arguments backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "arguments" renderer
+ INFO Book building has started
+ INFO Running the arguments backend
+ INFO Invoking the "arguments" renderer

 "#]]);
        });
@@ -156,9 +156,9 @@ fn backends_receive_render_context_via_stdin() {
    )
    .run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the cat-to-file backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "cat-to-file" renderer
+ INFO Book building has started
+ INFO Running the cat-to-file backend
+ INFO Invoking the "cat-to-file" renderer

 "#]]);
    })
@@ -233,9 +233,9 @@ fn relative_command_path() {
    )
    .run("build", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the myrenderer backend
-[TIMESTAMP] [INFO] (mdbook_driver::builtin_renderers): Invoking the "myrenderer" renderer
+ INFO Book building has started
+ INFO Running the myrenderer backend
+ INFO Invoking the "myrenderer" renderer

 "#]]);
    })
--- a/tests/testsuite/search.rs
+++ b/tests/testsuite/search.rs
@@ -126,10 +126,10 @@ fn with_no_source_path() {
 fn chapter_settings_validation_error() {
    BookTest::from_dir("search/chapter_settings_validation_error").run("build", |cmd| {
        cmd.expect_failure().expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: [output.html.search.chapter] key `does-not-exist` does not match any chapter paths
+ INFO Book building has started
+ INFO Running the html backend
+ERROR Rendering failed
+[TAB]Caused by: [output.html.search.chapter] key `does-not-exist` does not match any chapter paths

 "#]]);
    });
--- a/tests/testsuite/test.rs
+++ b/tests/testsuite/test.rs
@@ -7,9 +7,9 @@ use crate::prelude::*;
 fn passing_tests() {
    BookTest::from_dir("test/passing_tests").run("test", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Intro': "intro.md"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Passing 1': "passing1.md"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Passing 2': "passing2.md"
+ INFO Testing chapter 'Intro': "intro.md"
+ INFO Testing chapter 'Passing 1': "passing1.md"
+ INFO Testing chapter 'Passing 2': "passing2.md"

 "#]]);
    });
@@ -27,8 +27,8 @@ fn failing_tests() {
            // still includes a little bit of output, so if that is a problem,
            // add more redactions.
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Failing Tests': "failing.md"
-[TIMESTAMP] [ERROR] (mdbook_driver::mdbook): rustdoc returned an error:
+ INFO Testing chapter 'Failing Tests': "failing.md"
+ERROR rustdoc returned an error:

 --- stdout

@@ -38,8 +38,8 @@ test failing.md - Failing_Tests (line 3) ... FAILED
 thread [..] panicked at failing.md:3:1:
 fail
 ...
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Failing Include': "failing_include.md"
-[TIMESTAMP] [ERROR] (mdbook_driver::mdbook): rustdoc returned an error:
+ INFO Testing chapter 'Failing Include': "failing_include.md"
+ERROR rustdoc returned an error:

 --- stdout
 ...
@@ -48,7 +48,7 @@ test failing_include.md - Failing_Include (line 3) ... FAILED
 thread [..] panicked at failing_include.md:3:1:
 failing!
 ...
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: One or more tests failed
+ERROR One or more tests failed

 "#]]);
    });
@@ -62,14 +62,14 @@ fn test_individual_chapter() {
        cmd.args(&["Passing 1"])
            .expect_stdout(str![[""]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Passing 1': "passing1.md"
+ INFO Testing chapter 'Passing 1': "passing1.md"

 "#]]);
    })
    // Can also be a source path.
    .run("test -c passing2.md", |cmd| {
        cmd.expect_stdout(str![[""]]).expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Testing chapter 'Passing 2': "passing2.md"
+ INFO Testing chapter 'Passing 2': "passing2.md"

 "#]]);
    });
@@ -82,7 +82,7 @@ fn chapter_not_found() {
        cmd.expect_failure()
            .expect_stdout(str![[""]])
            .expect_stderr(str![[r#"
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Chapter not found: bogus
+ERROR Chapter not found: bogus

 "#]]);
    });
--- a/tests/testsuite/theme.rs
+++ b/tests/testsuite/theme.rs
@@ -5,14 +5,12 @@ use crate::prelude::*;
 // Checks what happens if the theme directory is missing.
 #[test]
 fn missing_theme() {
-    BookTest::from_dir("theme/missing_theme")
-    .run("build", |cmd| {
-cmd.expect_failure()
-        .expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [ERROR] (mdbook_core::utils): Error: Rendering failed
-[TIMESTAMP] [ERROR] (mdbook_core::utils): [TAB]Caused By: theme dir [ROOT]/./non-existent-directory does not exist
+    BookTest::from_dir("theme/missing_theme").run("build", |cmd| {
+        cmd.expect_failure().expect_stderr(str![[r#"
+ INFO Book building has started
+ INFO Running the html backend
+ERROR Rendering failed
+[TAB]Caused by: theme dir [ROOT]/./non-existent-directory does not exist

 "#]]);
    });
@@ -24,9 +22,9 @@ fn empty_theme() {
    BookTest::from_dir("theme/empty_theme").run("build", |cmd| {
        std::fs::create_dir(cmd.dir.join("theme")).unwrap();
        cmd.expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
    });
@@ -147,9 +145,9 @@ fn empty_fonts_css() {
    BookTest::from_dir("theme/empty_fonts_css")
        .run("build", |cmd| {
            cmd.expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
        })
@@ -163,9 +161,9 @@ fn custom_fonts_css() {
    BookTest::from_dir("theme/custom_fonts_css")
        .run("build", |cmd| {
            cmd.expect_stderr(str![[r#"
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Book building has started
-[TIMESTAMP] [INFO] (mdbook_driver::mdbook): Running the html backend
-[TIMESTAMP] [INFO] (mdbook_html::html_handlebars::hbs_renderer): HTML book written to `[ROOT]/book`
+ INFO Book building has started
+ INFO Running the html backend
+ INFO HTML book written to `[ROOT]/book`

 "#]]);
        })