Auto merge of #3733 - rust-lang:rustup-2024-07-05, r=RalfJung

Automatic Rustup

39 files changed, 448 insertions, 397 deletions

diff --git a/src/bootstrap/src/core/build_steps/compile.rs b/src/bootstrap/src/core/build_steps/compile.rs
index de3b938e427..01b25224de4 100644
--- a/src/bootstrap/src/core/build_steps/compile.rs
+++ b/src/bootstrap/src/core/build_steps/compile.rs
@@ -29,7 +29,7 @@ use crate::core::builder::{Builder, Kind, PathSet, RunConfig, ShouldRun, Step, T
 use crate::core::config::{DebuginfoLevel, LlvmLibunwind, RustcLto, TargetSelection};
 use crate::utils::exec::BootstrapCommand;
 use crate::utils::helpers::{
-    exe, get_clang_cl_resource_dir, is_debug_info, is_dylib, output, symlink_dir, t, up_to_date,
+    exe, get_clang_cl_resource_dir, is_debug_info, is_dylib, symlink_dir, t, up_to_date,
 };
 use crate::LLVM_TOOLS;
 use crate::{CLang, Compiler, DependencyType, GitRepo, Mode};
@@ -1488,10 +1488,10 @@ pub fn compiler_file(
     if builder.config.dry_run() {
         return PathBuf::new();
     }
-    let mut cmd = Command::new(compiler);
+    let mut cmd = BootstrapCommand::new(compiler);
     cmd.args(builder.cflags(target, GitRepo::Rustc, c));
     cmd.arg(format!("-print-file-name={file}"));
-    let out = output(&mut cmd);
+    let out = builder.run(cmd.capture_stdout()).stdout();
     PathBuf::from(out.trim())
 }
 
@@ -1836,7 +1836,9 @@ impl Step for Assemble {
             let llvm::LlvmResult { llvm_config, .. } =
                 builder.ensure(llvm::Llvm { target: target_compiler.host });
             if !builder.config.dry_run() && builder.config.llvm_tools_enabled {
-                let llvm_bin_dir = output(Command::new(llvm_config).arg("--bindir"));
+                let llvm_bin_dir = builder
+                    .run(BootstrapCommand::new(llvm_config).capture_stdout().arg("--bindir"))
+                    .stdout();
                 let llvm_bin_dir = Path::new(llvm_bin_dir.trim());
 
                 // Since we've already built the LLVM tools, install them to the sysroot.
@@ -2080,7 +2082,7 @@ pub fn stream_cargo(
     tail_args: Vec<String>,
     cb: &mut dyn FnMut(CargoMessage<'_>),
 ) -> bool {
-    let mut cargo = BootstrapCommand::from(cargo).command;
+    let mut cargo = cargo.into_cmd().command;
     // Instruct Cargo to give us json messages on stdout, critically leaving
     // stderr as piped so we can get those pretty colors.
     let mut message_format = if builder.config.json_output {
@@ -2161,8 +2163,7 @@ pub fn strip_debug(builder: &Builder<'_>, target: TargetSelection, path: &Path)
     }
 
     let previous_mtime = FileTime::from_last_modification_time(&path.metadata().unwrap());
-    // NOTE: `output` will propagate any errors here.
-    output(Command::new("strip").arg("--strip-debug").arg(path));
+    builder.run(BootstrapCommand::new("strip").capture().arg("--strip-debug").arg(path));
 
     // After running `strip`, we have to set the file modification time to what it was before,
     // otherwise we risk Cargo invalidating its fingerprint and rebuilding the world next time
diff --git a/src/bootstrap/src/core/build_steps/dist.rs b/src/bootstrap/src/core/build_steps/dist.rs
index 08795efe5bb..3dc871b1ca9 100644
--- a/src/bootstrap/src/core/build_steps/dist.rs
+++ b/src/bootstrap/src/core/build_steps/dist.rs
@@ -14,7 +14,6 @@ use std::ffi::OsStr;
 use std::fs;
 use std::io::Write;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 
 use object::read::archive::ArchiveFile;
 use object::BinaryFormat;
@@ -28,7 +27,7 @@ use crate::core::config::TargetSelection;
 use crate::utils::channel::{self, Info};
 use crate::utils::exec::BootstrapCommand;
 use crate::utils::helpers::{
-    exe, is_dylib, move_file, output, t, target_supports_cranelift_backend, timeit,
+    exe, is_dylib, move_file, t, target_supports_cranelift_backend, timeit,
 };
 use crate::utils::tarball::{GeneratedTarball, OverlayKind, Tarball};
 use crate::{Compiler, DependencyType, Mode, LLVM_TOOLS};
@@ -181,9 +180,9 @@ fn make_win_dist(
     }
 
     //Ask gcc where it keeps its stuff
-    let mut cmd = Command::new(builder.cc(target));
+    let mut cmd = BootstrapCommand::new(builder.cc(target));
     cmd.arg("-print-search-dirs");
-    let gcc_out = output(&mut cmd);
+    let gcc_out = builder.run(cmd.capture_stdout()).stdout();
 
     let mut bin_path: Vec<_> = env::split_paths(&env::var_os("PATH").unwrap_or_default()).collect();
     let mut lib_path = Vec::new();
@@ -1024,7 +1023,7 @@ impl Step for PlainSourceTarball {
             }
 
             // Vendor all Cargo dependencies
-            let mut cmd = Command::new(&builder.initial_cargo);
+            let mut cmd = BootstrapCommand::new(&builder.initial_cargo);
             cmd.arg("vendor")
                 .arg("--versioned-dirs")
                 .arg("--sync")
@@ -1062,7 +1061,7 @@ impl Step for PlainSourceTarball {
             }
 
             let config = if !builder.config.dry_run() {
-                t!(String::from_utf8(t!(cmd.output()).stdout))
+                builder.run(cmd.capture()).stdout()
             } else {
                 String::new()
             };
@@ -2079,10 +2078,14 @@ fn maybe_install_llvm(
     } else if let llvm::LlvmBuildStatus::AlreadyBuilt(llvm::LlvmResult { llvm_config, .. }) =
         llvm::prebuilt_llvm_config(builder, target)
     {
-        let mut cmd = Command::new(llvm_config);
+        let mut cmd = BootstrapCommand::new(llvm_config);
         cmd.arg("--libfiles");
         builder.verbose(|| println!("running {cmd:?}"));
-        let files = if builder.config.dry_run() { "".into() } else { output(&mut cmd) };
+        let files = if builder.config.dry_run() {
+            "".into()
+        } else {
+            builder.run(cmd.capture_stdout()).stdout()
+        };
         let build_llvm_out = &builder.llvm_out(builder.config.build);
         let target_llvm_out = &builder.llvm_out(target);
         for file in files.trim_end().split(' ') {
diff --git a/src/bootstrap/src/core/build_steps/doc.rs b/src/bootstrap/src/core/build_steps/doc.rs
index 4a5af25b3b2..823e842693e 100644
--- a/src/bootstrap/src/core/build_steps/doc.rs
+++ b/src/bootstrap/src/core/build_steps/doc.rs
@@ -738,7 +738,7 @@ fn doc_std(
         format!("library{} in {} format", crate_description(requested_crates), format.as_str());
     let _guard = builder.msg_doc(compiler, description, target);
 
-    builder.run(cargo);
+    builder.run(cargo.into_cmd());
     builder.cp_link_r(&out_dir, out);
 }
 
@@ -863,7 +863,7 @@ impl Step for Rustc {
         let proc_macro_out_dir = builder.stage_out(compiler, Mode::Rustc).join("doc");
         symlink_dir_force(&builder.config, &out, &proc_macro_out_dir);
 
-        builder.run(cargo);
+        builder.run(cargo.into_cmd());
 
         if !builder.config.dry_run() {
             // Sanity check on linked compiler crates
@@ -996,7 +996,7 @@ macro_rules! tool_doc {
                 symlink_dir_force(&builder.config, &out, &proc_macro_out_dir);
 
                 let _guard = builder.msg_doc(compiler, stringify!($tool).to_lowercase(), target);
-                builder.run(cargo);
+                builder.run(cargo.into_cmd());
 
                 if !builder.config.dry_run() {
                     // Sanity check on linked doc directories
diff --git a/src/bootstrap/src/core/build_steps/format.rs b/src/bootstrap/src/core/build_steps/format.rs
index f5e34672686..66286a52813 100644
--- a/src/bootstrap/src/core/build_steps/format.rs
+++ b/src/bootstrap/src/core/build_steps/format.rs
@@ -1,13 +1,14 @@
 //! Runs rustfmt on the repository.
 
 use crate::core::builder::Builder;
-use crate::utils::helpers::{self, output, program_out_of_date, t};
+use crate::utils::exec::BootstrapCommand;
+use crate::utils::helpers::{self, program_out_of_date, t};
 use build_helper::ci::CiEnv;
 use build_helper::git::get_git_modified_files;
 use ignore::WalkBuilder;
 use std::collections::VecDeque;
 use std::path::{Path, PathBuf};
-use std::process::{Command, Stdio};
+use std::process::Command;
 use std::sync::mpsc::SyncSender;
 use std::sync::Mutex;
 
@@ -53,19 +54,17 @@ fn rustfmt(src: &Path, rustfmt: &Path, paths: &[PathBuf], check: bool) -> impl F
 fn get_rustfmt_version(build: &Builder<'_>) -> Option<(String, PathBuf)> {
     let stamp_file = build.out.join("rustfmt.stamp");
 
-    let mut cmd = Command::new(match build.initial_rustfmt() {
+    let mut cmd = BootstrapCommand::new(match build.initial_rustfmt() {
         Some(p) => p,
         None => return None,
     });
     cmd.arg("--version");
-    let output = match cmd.output() {
-        Ok(status) => status,
-        Err(_) => return None,
-    };
-    if !output.status.success() {
+
+    let output = build.run(cmd.capture().allow_failure());
+    if output.is_failure() {
         return None;
     }
-    Some((String::from_utf8(output.stdout).unwrap(), stamp_file))
+    Some((output.stdout(), stamp_file))
 }
 
 /// Return whether the format cache can be reused.
@@ -160,36 +159,31 @@ pub fn format(build: &Builder<'_>, check: bool, all: bool, paths: &[PathBuf]) {
             override_builder.add(&format!("!{ignore}")).expect(&ignore);
         }
     }
-    let git_available = match helpers::git(None)
-        .arg("--version")
-        .stdout(Stdio::null())
-        .stderr(Stdio::null())
-        .status()
-    {
-        Ok(status) => status.success(),
-        Err(_) => false,
-    };
+    let git_available =
+        build.run(helpers::git(None).capture().allow_failure().arg("--version")).is_success();
 
     let mut adjective = None;
     if git_available {
-        let in_working_tree = match helpers::git(Some(&build.src))
-            .arg("rev-parse")
-            .arg("--is-inside-work-tree")
-            .stdout(Stdio::null())
-            .stderr(Stdio::null())
-            .status()
-        {
-            Ok(status) => status.success(),
-            Err(_) => false,
-        };
-        if in_working_tree {
-            let untracked_paths_output = output(
+        let in_working_tree = build
+            .run(
                 helpers::git(Some(&build.src))
-                    .arg("status")
-                    .arg("--porcelain")
-                    .arg("-z")
-                    .arg("--untracked-files=normal"),
-            );
+                    .capture()
+                    .allow_failure()
+                    .arg("rev-parse")
+                    .arg("--is-inside-work-tree"),
+            )
+            .is_success();
+        if in_working_tree {
+            let untracked_paths_output = build
+                .run(
+                    helpers::git(Some(&build.src))
+                        .capture_stdout()
+                        .arg("status")
+                        .arg("--porcelain")
+                        .arg("-z")
+                        .arg("--untracked-files=normal"),
+                )
+                .stdout();
             let untracked_paths: Vec<_> = untracked_paths_output
                 .split_terminator('\0')
                 .filter_map(
diff --git a/src/bootstrap/src/core/build_steps/llvm.rs b/src/bootstrap/src/core/build_steps/llvm.rs
index 8e6795b11bd..4f1c1f87d1c 100644
--- a/src/bootstrap/src/core/build_steps/llvm.rs
+++ b/src/bootstrap/src/core/build_steps/llvm.rs
@@ -14,7 +14,6 @@ use std::ffi::{OsStr, OsString};
 use std::fs::{self, File};
 use std::io;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 use std::sync::OnceLock;
 
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
@@ -25,6 +24,7 @@ use crate::utils::helpers::{
 };
 use crate::{generate_smart_stamp_hash, CLang, GitRepo, Kind};
 
+use crate::utils::exec::BootstrapCommand;
 use build_helper::ci::CiEnv;
 use build_helper::git::get_git_merge_base;
 
@@ -172,7 +172,7 @@ pub(crate) fn detect_llvm_sha(config: &Config, is_git: bool) -> String {
             // the LLVM shared object file is named `LLVM-12-rust-{version}-nightly`
             config.src.join("src/version"),
         ]);
-        output(&mut rev_list).trim().to_owned()
+        output(&mut rev_list.command).trim().to_owned()
     } else if let Some(info) = channel::read_commit_info_file(&config.src) {
         info.sha.trim().to_owned()
     } else {
@@ -253,7 +253,8 @@ pub(crate) fn is_ci_llvm_modified(config: &Config) -> bool {
         // We assume we have access to git, so it's okay to unconditionally pass
         // `true` here.
         let llvm_sha = detect_llvm_sha(config, true);
-        let head_sha = output(helpers::git(Some(&config.src)).arg("rev-parse").arg("HEAD"));
+        let head_sha =
+            output(&mut helpers::git(Some(&config.src)).arg("rev-parse").arg("HEAD").command);
         let head_sha = head_sha.trim();
         llvm_sha == head_sha
     }
@@ -477,7 +478,9 @@ impl Step for Llvm {
             let LlvmResult { llvm_config, .. } =
                 builder.ensure(Llvm { target: builder.config.build });
             if !builder.config.dry_run() {
-                let llvm_bindir = output(Command::new(&llvm_config).arg("--bindir"));
+                let llvm_bindir = builder
+                    .run(BootstrapCommand::new(&llvm_config).capture_stdout().arg("--bindir"))
+                    .stdout();
                 let host_bin = Path::new(llvm_bindir.trim());
                 cfg.define(
                     "LLVM_TABLEGEN",
@@ -527,8 +530,8 @@ impl Step for Llvm {
 
         // Helper to find the name of LLVM's shared library on darwin and linux.
         let find_llvm_lib_name = |extension| {
-            let mut cmd = Command::new(&res.llvm_config);
-            let version = output(cmd.arg("--version"));
+            let cmd = BootstrapCommand::new(&res.llvm_config);
+            let version = builder.run(cmd.capture_stdout().arg("--version")).stdout();
             let major = version.split('.').next().unwrap();
 
             match &llvm_version_suffix {
@@ -584,8 +587,8 @@ fn check_llvm_version(builder: &Builder<'_>, llvm_config: &Path) {
         return;
     }
 
-    let mut cmd = Command::new(llvm_config);
-    let version = output(cmd.arg("--version"));
+    let cmd = BootstrapCommand::new(llvm_config);
+    let version = builder.run(cmd.capture_stdout().arg("--version")).stdout();
     let mut parts = version.split('.').take(2).filter_map(|s| s.parse::<u32>().ok());
     if let (Some(major), Some(_minor)) = (parts.next(), parts.next()) {
         if major >= 17 {
diff --git a/src/bootstrap/src/core/build_steps/run.rs b/src/bootstrap/src/core/build_steps/run.rs
index 22d5efa5d95..316a03a2171 100644
--- a/src/bootstrap/src/core/build_steps/run.rs
+++ b/src/bootstrap/src/core/build_steps/run.rs
@@ -4,7 +4,6 @@
 //! If it can be reached from `./x.py run` it can go here.
 
 use std::path::PathBuf;
-use std::process::Command;
 
 use crate::core::build_steps::dist::distdir;
 use crate::core::build_steps::test;
@@ -12,7 +11,7 @@ use crate::core::build_steps::tool::{self, SourceType, Tool};
 use crate::core::builder::{Builder, RunConfig, ShouldRun, Step};
 use crate::core::config::flags::get_completion;
 use crate::core::config::TargetSelection;
-use crate::utils::helpers::output;
+use crate::utils::exec::BootstrapCommand;
 use crate::Mode;
 
 #[derive(Debug, PartialOrd, Ord, Clone, Hash, PartialEq, Eq)]
@@ -41,7 +40,8 @@ impl Step for BuildManifest {
             panic!("\n\nfailed to specify `dist.upload-addr` in `config.toml`\n\n")
         });
 
-        let today = output(Command::new("date").arg("+%Y-%m-%d"));
+        let today =
+            builder.run(BootstrapCommand::new("date").capture_stdout().arg("+%Y-%m-%d")).stdout();
 
         cmd.arg(sign);
         cmd.arg(distdir(builder));
@@ -158,7 +158,7 @@ impl Step for Miri {
         // after another --, so this must be at the end.
         miri.args(builder.config.args());
 
-        builder.run(miri);
+        builder.run(miri.into_cmd());
     }
 }
 
diff --git a/src/bootstrap/src/core/build_steps/setup.rs b/src/bootstrap/src/core/build_steps/setup.rs
index 947c74f32c9..e6a09e8cb8e 100644
--- a/src/bootstrap/src/core/build_steps/setup.rs
+++ b/src/bootstrap/src/core/build_steps/setup.rs
@@ -484,6 +484,7 @@ impl Step for Hook {
 fn install_git_hook_maybe(config: &Config) -> io::Result<()> {
     let git = helpers::git(Some(&config.src))
         .args(["rev-parse", "--git-common-dir"])
+        .command
         .output()
         .map(|output| {
             assert!(output.status.success(), "failed to run `git`");
diff --git a/src/bootstrap/src/core/build_steps/suggest.rs b/src/bootstrap/src/core/build_steps/suggest.rs
index 7c5e0d4e13e..5412b3c807b 100644
--- a/src/bootstrap/src/core/build_steps/suggest.rs
+++ b/src/bootstrap/src/core/build_steps/suggest.rs
@@ -13,24 +13,15 @@ use crate::core::builder::Builder;
 pub fn suggest(builder: &Builder<'_>, run: bool) {
     let git_config = builder.config.git_config();
     let suggestions = builder
-        .tool_cmd(Tool::SuggestTests)
-        .env("SUGGEST_TESTS_GIT_REPOSITORY", git_config.git_repository)
-        .env("SUGGEST_TESTS_NIGHTLY_BRANCH", git_config.nightly_branch)
-        .command
-        .output()
-        .expect("failed to run `suggest-tests` tool");
+        .run(
+            builder
+                .tool_cmd(Tool::SuggestTests)
+                .capture_stdout()
+                .env("SUGGEST_TESTS_GIT_REPOSITORY", git_config.git_repository)
+                .env("SUGGEST_TESTS_NIGHTLY_BRANCH", git_config.nightly_branch),
+        )
+        .stdout();
 
-    if !suggestions.status.success() {
-        println!("failed to run `suggest-tests` tool ({})", suggestions.status);
-        println!(
-            "`suggest_tests` stdout:\n{}`suggest_tests` stderr:\n{}",
-            String::from_utf8(suggestions.stdout).unwrap(),
-            String::from_utf8(suggestions.stderr).unwrap()
-        );
-        panic!("failed to run `suggest-tests`");
-    }
-
-    let suggestions = String::from_utf8(suggestions.stdout).unwrap();
     let suggestions = suggestions
         .lines()
         .map(|line| {
diff --git a/src/bootstrap/src/core/build_steps/synthetic_targets.rs b/src/bootstrap/src/core/build_steps/synthetic_targets.rs
index 281a9b093b9..a115ba2d8b2 100644
--- a/src/bootstrap/src/core/build_steps/synthetic_targets.rs
+++ b/src/bootstrap/src/core/build_steps/synthetic_targets.rs
@@ -9,8 +9,8 @@
 
 use crate::core::builder::{Builder, ShouldRun, Step};
 use crate::core::config::TargetSelection;
+use crate::utils::exec::BootstrapCommand;
 use crate::Compiler;
-use std::process::{Command, Stdio};
 
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
 pub(crate) struct MirOptPanicAbortSyntheticTarget {
@@ -56,7 +56,7 @@ fn create_synthetic_target(
         return TargetSelection::create_synthetic(&name, path.to_str().unwrap());
     }
 
-    let mut cmd = Command::new(builder.rustc(compiler));
+    let mut cmd = BootstrapCommand::new(builder.rustc(compiler));
     cmd.arg("--target").arg(base.rustc_target_arg());
     cmd.args(["-Zunstable-options", "--print", "target-spec-json"]);
 
@@ -64,14 +64,8 @@ fn create_synthetic_target(
     // we cannot use nightly features. So `RUSTC_BOOTSTRAP` is needed here.
     cmd.env("RUSTC_BOOTSTRAP", "1");
 
-    cmd.stdout(Stdio::piped());
-
-    let output = cmd.spawn().unwrap().wait_with_output().unwrap();
-    if !output.status.success() {
-        panic!("failed to gather the target spec for {base}");
-    }
-
-    let mut spec: serde_json::Value = serde_json::from_slice(&output.stdout).unwrap();
+    let output = builder.run(cmd.capture()).stdout();
+    let mut spec: serde_json::Value = serde_json::from_slice(output.as_bytes()).unwrap();
     let spec_map = spec.as_object_mut().unwrap();
 
     // The `is-builtin` attribute of a spec needs to be removed, otherwise rustc will complain.
diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs
index 1460a229019..dc53bd3cfa7 100644
--- a/src/bootstrap/src/core/build_steps/test.rs
+++ b/src/bootstrap/src/core/build_steps/test.rs
@@ -26,11 +26,10 @@ use crate::core::builder::{Builder, Compiler, Kind, RunConfig, ShouldRun, Step};
 use crate::core::config::flags::get_completion;
 use crate::core::config::flags::Subcommand;
 use crate::core::config::TargetSelection;
-use crate::utils::exec::{BootstrapCommand, OutputMode};
+use crate::utils::exec::BootstrapCommand;
 use crate::utils::helpers::{
     self, add_link_lib_path, add_rustdoc_cargo_linker_args, dylib_path, dylib_path_var,
-    linker_args, linker_flags, output, t, target_supports_cranelift_backend, up_to_date,
-    LldThreads,
+    linker_args, linker_flags, t, target_supports_cranelift_backend, up_to_date, LldThreads,
 };
 use crate::utils::render_tests::{add_flags_and_try_run_tests, try_run_tests};
 use crate::{envify, CLang, DocTests, GitRepo, Mode};
@@ -150,16 +149,13 @@ You can skip linkcheck with --skip src/tools/linkchecker"
         builder.default_doc(&[]);
 
         // Build the linkchecker before calling `msg`, since GHA doesn't support nested groups.
-        let mut linkchecker = builder.tool_cmd(Tool::Linkchecker);
+        let linkchecker = builder.tool_cmd(Tool::Linkchecker);
 
         // Run the linkchecker.
         let _guard =
             builder.msg(Kind::Test, compiler.stage, "Linkcheck", bootstrap_host, bootstrap_host);
         let _time = helpers::timeit(builder);
-        builder.run(
-            BootstrapCommand::from(linkchecker.arg(builder.out.join(host.triple).join("doc")))
-                .delay_failure(),
-        );
+        builder.run(linkchecker.delay_failure().arg(builder.out.join(host.triple).join("doc")));
     }
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
@@ -217,10 +213,7 @@ impl Step for HtmlCheck {
         ));
 
         builder.run(
-            BootstrapCommand::from(
-                builder.tool_cmd(Tool::HtmlChecker).arg(builder.doc_out(self.target)),
-            )
-            .delay_failure(),
+            builder.tool_cmd(Tool::HtmlChecker).delay_failure().arg(builder.doc_out(self.target)),
         );
     }
 }
@@ -260,14 +253,13 @@ impl Step for Cargotest {
 
         let _time = helpers::timeit(builder);
         let mut cmd = builder.tool_cmd(Tool::CargoTest);
-        let cmd = cmd
-            .arg(&cargo)
+        cmd.arg(&cargo)
             .arg(&out_dir)
             .args(builder.config.test_args())
             .env("RUSTC", builder.rustc(compiler))
             .env("RUSTDOC", builder.rustdoc(compiler));
-        add_rustdoc_cargo_linker_args(cmd, builder, compiler.host, LldThreads::No);
-        builder.run(BootstrapCommand::from(cmd).delay_failure());
+        add_rustdoc_cargo_linker_args(&mut cmd, builder, compiler.host, LldThreads::No);
+        builder.run(cmd.delay_failure());
     }
 }
 
@@ -477,19 +469,12 @@ impl Miri {
         // We re-use the `cargo` from above.
         cargo.arg("--print-sysroot");
 
-        // FIXME: Is there a way in which we can re-use the usual `run` helpers?
         if builder.config.dry_run() {
             String::new()
         } else {
             builder.verbose(|| println!("running: {cargo:?}"));
-            let out = cargo
-                .command
-                .output()
-                .expect("We already ran `cargo miri setup` before and that worked");
-            assert!(out.status.success(), "`cargo miri setup` returned with non-0 exit code");
+            let stdout = builder.run(cargo.capture_stdout()).stdout();
             // Output is "<sysroot>\n".
-            let stdout = String::from_utf8(out.stdout)
-                .expect("`cargo miri setup` stdout is not valid UTF-8");
             let sysroot = stdout.trim_end();
             builder.verbose(|| println!("`cargo miri setup --print-sysroot` said: {sysroot:?}"));
             sysroot.to_owned()
@@ -763,12 +748,12 @@ impl Step for Clippy {
         cargo.env("HOST_LIBS", host_libs);
 
         cargo.add_rustc_lib_path(builder);
-        let mut cargo = prepare_cargo_test(cargo, &[], &[], "clippy", compiler, host, builder);
+        let cargo = prepare_cargo_test(cargo, &[], &[], "clippy", compiler, host, builder);
 
         let _guard = builder.msg_sysroot_tool(Kind::Test, compiler.stage, "clippy", host, host);
 
         // Clippy reports errors if it blessed the outputs
-        if builder.run(BootstrapCommand::from(&mut cargo).allow_failure()).is_success() {
+        if builder.run(cargo.allow_failure()).is_success() {
             // The tests succeeded; nothing to do.
             return;
         }
@@ -821,7 +806,7 @@ impl Step for RustdocTheme {
             .env("RUSTC_BOOTSTRAP", "1");
         cmd.args(linker_args(builder, self.compiler.host, LldThreads::No));
 
-        builder.run(BootstrapCommand::from(&mut cmd).delay_failure());
+        builder.run(cmd.delay_failure());
     }
 }
 
@@ -918,25 +903,26 @@ impl Step for RustdocJSNotStd {
     }
 }
 
-fn get_browser_ui_test_version_inner(npm: &Path, global: bool) -> Option<String> {
-    let mut command = Command::new(npm);
+fn get_browser_ui_test_version_inner(
+    builder: &Builder<'_>,
+    npm: &Path,
+    global: bool,
+) -> Option<String> {
+    let mut command = BootstrapCommand::new(npm).capture();
     command.arg("list").arg("--parseable").arg("--long").arg("--depth=0");
     if global {
         command.arg("--global");
     }
-    let lines = command
-        .output()
-        .map(|output| String::from_utf8_lossy(&output.stdout).into_owned())
-        .unwrap_or_default();
+    let lines = builder.run(command.allow_failure()).stdout();
     lines
         .lines()
         .find_map(|l| l.split(':').nth(1)?.strip_prefix("browser-ui-test@"))
         .map(|v| v.to_owned())
 }
 
-fn get_browser_ui_test_version(npm: &Path) -> Option<String> {
-    get_browser_ui_test_version_inner(npm, false)
-        .or_else(|| get_browser_ui_test_version_inner(npm, true))
+fn get_browser_ui_test_version(builder: &Builder<'_>, npm: &Path) -> Option<String> {
+    get_browser_ui_test_version_inner(builder, npm, false)
+        .or_else(|| get_browser_ui_test_version_inner(builder, npm, true))
 }
 
 #[derive(Debug, Clone, Hash, PartialEq, Eq)]
@@ -960,7 +946,7 @@ impl Step for RustdocGUI {
                     .config
                     .npm
                     .as_ref()
-                    .map(|p| get_browser_ui_test_version(p).is_some())
+                    .map(|p| get_browser_ui_test_version(builder, p).is_some())
                     .unwrap_or(false)
         }))
     }
@@ -1099,7 +1085,7 @@ HELP: to skip test's attempt to check tidiness, pass `--skip src/tools/tidy` to
         }
 
         builder.info("tidy check");
-        builder.run(BootstrapCommand::from(&mut cmd).delay_failure());
+        builder.run(cmd.delay_failure());
 
         builder.info("x.py completions check");
         let [bash, zsh, fish, powershell] = ["x.py.sh", "x.py.zsh", "x.py.fish", "x.py.ps1"]
@@ -1306,7 +1292,7 @@ impl Step for RunMakeSupport {
             &[],
         );
 
-        builder.run(cargo);
+        builder.run(cargo.into_cmd());
 
         let lib_name = "librun_make_support.rlib";
         let lib = builder.tools_dir(self.compiler).join(lib_name);
@@ -1818,26 +1804,16 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
         }
 
         let lldb_exe = builder.config.lldb.clone().unwrap_or_else(|| PathBuf::from("lldb"));
-        let lldb_version = Command::new(&lldb_exe)
-            .arg("--version")
-            .output()
-            .map(|output| {
-                (String::from_utf8_lossy(&output.stdout).to_string(), output.status.success())
-            })
-            .ok()
-            .and_then(|(output, success)| if success { Some(output) } else { None });
+        let lldb_version = builder
+            .run(BootstrapCommand::new(&lldb_exe).capture().allow_failure().arg("--version"))
+            .stdout_if_ok()
+            .and_then(|v| if v.trim().is_empty() { None } else { Some(v) });
         if let Some(ref vers) = lldb_version {
-            let run = |cmd: &mut Command| {
-                cmd.output().map(|output| {
-                    String::from_utf8_lossy(&output.stdout)
-                        .lines()
-                        .next()
-                        .unwrap_or_else(|| panic!("{:?} failed {:?}", cmd, output))
-                        .to_string()
-                })
-            };
             cmd.arg("--lldb-version").arg(vers);
-            let lldb_python_dir = run(Command::new(&lldb_exe).arg("-P")).ok();
+            let lldb_python_dir = builder
+                .run(BootstrapCommand::new(&lldb_exe).allow_failure().capture_stdout().arg("-P"))
+                .stdout_if_ok()
+                .map(|p| p.lines().next().expect("lldb Python dir not found").to_string());
             if let Some(ref dir) = lldb_python_dir {
                 cmd.arg("--lldb-python-dir").arg(dir);
             }
@@ -1893,8 +1869,12 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
             let llvm::LlvmResult { llvm_config, .. } =
                 builder.ensure(llvm::Llvm { target: builder.config.build });
             if !builder.config.dry_run() {
-                let llvm_version = output(Command::new(&llvm_config).arg("--version"));
-                let llvm_components = output(Command::new(&llvm_config).arg("--components"));
+                let llvm_version = builder
+                    .run(BootstrapCommand::new(&llvm_config).capture_stdout().arg("--version"))
+                    .stdout();
+                let llvm_components = builder
+                    .run(BootstrapCommand::new(&llvm_config).capture_stdout().arg("--components"))
+                    .stdout();
                 // Remove trailing newline from llvm-config output.
                 cmd.arg("--llvm-version")
                     .arg(llvm_version.trim())
@@ -1913,7 +1893,9 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
             // separate compilations. We can add LLVM's library path to the
             // platform-specific environment variable as a workaround.
             if !builder.config.dry_run() && suite.ends_with("fulldeps") {
-                let llvm_libdir = output(Command::new(&llvm_config).arg("--libdir"));
+                let llvm_libdir = builder
+                    .run(BootstrapCommand::new(&llvm_config).capture_stdout().arg("--libdir"))
+                    .stdout();
                 add_link_lib_path(vec![llvm_libdir.trim().into()], &mut cmd);
             }
 
@@ -2187,7 +2169,7 @@ impl BookTest {
             compiler.host,
         );
         let _time = helpers::timeit(builder);
-        let cmd = BootstrapCommand::from(&mut rustbook_cmd).delay_failure();
+        let cmd = rustbook_cmd.delay_failure();
         let toolstate =
             if builder.run(cmd).is_success() { ToolState::TestPass } else { ToolState::TestFail };
         builder.save_toolstate(self.name, toolstate);
@@ -2318,7 +2300,7 @@ impl Step for ErrorIndex {
         let guard =
             builder.msg(Kind::Test, compiler.stage, "error-index", compiler.host, compiler.host);
         let _time = helpers::timeit(builder);
-        builder.run(BootstrapCommand::from(&mut tool).output_mode(OutputMode::OnlyOnFailure));
+        builder.run(tool.capture());
         drop(guard);
         // The tests themselves need to link to std, so make sure it is
         // available.
@@ -2349,7 +2331,7 @@ fn markdown_test(builder: &Builder<'_>, compiler: Compiler, markdown: &Path) ->
 
     cmd = cmd.delay_failure();
     if !builder.config.verbose_tests {
-        cmd = cmd.quiet();
+        cmd = cmd.capture();
     }
     builder.run(cmd).is_success()
 }
@@ -2375,10 +2357,13 @@ impl Step for RustcGuide {
         builder.update_submodule(&relative_path);
 
         let src = builder.src.join(relative_path);
-        let mut rustbook_cmd = builder.tool_cmd(Tool::Rustbook);
-        let cmd = BootstrapCommand::from(rustbook_cmd.arg("linkcheck").arg(&src)).delay_failure();
-        let toolstate =
-            if builder.run(cmd).is_success() { ToolState::TestPass } else { ToolState::TestFail };
+        let mut rustbook_cmd = builder.tool_cmd(Tool::Rustbook).delay_failure();
+        rustbook_cmd.arg("linkcheck").arg(&src);
+        let toolstate = if builder.run(rustbook_cmd).is_success() {
+            ToolState::TestPass
+        } else {
+            ToolState::TestFail
+        };
         builder.save_toolstate("rustc-dev-guide", toolstate);
     }
 }
@@ -3347,7 +3332,7 @@ impl Step for CodegenCranelift {
             .arg("testsuite.extended_sysroot");
         cargo.args(builder.config.test_args());
 
-        builder.run(cargo);
+        builder.run(cargo.into_cmd());
     }
 }
 
@@ -3472,6 +3457,6 @@ impl Step for CodegenGCC {
             .arg("--std-tests");
         cargo.args(builder.config.test_args());
 
-        builder.run(cargo);
+        builder.run(cargo.into_cmd());
     }
 }
diff --git a/src/bootstrap/src/core/build_steps/tool.rs b/src/bootstrap/src/core/build_steps/tool.rs
index b3464043912..5fb282db90a 100644
--- a/src/bootstrap/src/core/build_steps/tool.rs
+++ b/src/bootstrap/src/core/build_steps/tool.rs
@@ -1,7 +1,6 @@
 use std::env;
 use std::fs;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 
 use crate::core::build_steps::compile;
 use crate::core::build_steps::toolstate::ToolState;
@@ -10,7 +9,6 @@ use crate::core::builder::{Builder, Cargo as CargoCommand, RunConfig, ShouldRun,
 use crate::core::config::TargetSelection;
 use crate::utils::channel::GitInfo;
 use crate::utils::exec::BootstrapCommand;
-use crate::utils::helpers::output;
 use crate::utils::helpers::{add_dylib_path, exe, t};
 use crate::Compiler;
 use crate::Mode;
@@ -246,6 +244,7 @@ macro_rules! bootstrap_tool {
         ;
     )+) => {
         #[derive(PartialEq, Eq, Clone)]
+        #[allow(dead_code)]
         pub enum Tool {
             $(
                 $name,
@@ -603,7 +602,7 @@ impl Step for Rustdoc {
             &self.compiler.host,
             &target,
         );
-        builder.run(cargo);
+        builder.run(cargo.into_cmd());
 
         // Cargo adds a number of paths to the dylib search path on windows, which results in
         // the wrong rustdoc being executed. To avoid the conflicting rustdocs, we name the "tool"
@@ -858,7 +857,7 @@ impl Step for LlvmBitcodeLinker {
             &self.extra_features,
         );
 
-        builder.run(cargo);
+        builder.run(cargo.into_cmd());
 
         let tool_out = builder
             .cargo_out(self.compiler, Mode::ToolRustc, self.target)
@@ -926,7 +925,8 @@ impl Step for LibcxxVersionTool {
             }
         }
 
-        let version_output = output(&mut Command::new(executable));
+        let version_output =
+            builder.run(BootstrapCommand::new(executable).capture_stdout()).stdout();
 
         let version_str = version_output.split_once("version:").unwrap().1;
         let version = version_str.trim().parse::<usize>().unwrap();
diff --git a/src/bootstrap/src/core/build_steps/toolstate.rs b/src/bootstrap/src/core/build_steps/toolstate.rs
index 9e6d03349b5..e3e7931a5a2 100644
--- a/src/bootstrap/src/core/build_steps/toolstate.rs
+++ b/src/bootstrap/src/core/build_steps/toolstate.rs
@@ -101,8 +101,13 @@ fn print_error(tool: &str, submodule: &str) {
 
 fn check_changed_files(toolstates: &HashMap<Box<str>, ToolState>) {
     // Changed files
-    let output =
-        helpers::git(None).arg("diff").arg("--name-status").arg("HEAD").arg("HEAD^").output();
+    let output = helpers::git(None)
+        .arg("diff")
+        .arg("--name-status")
+        .arg("HEAD")
+        .arg("HEAD^")
+        .command
+        .output();
     let output = match output {
         Ok(o) => o,
         Err(e) => {
@@ -324,6 +329,7 @@ fn checkout_toolstate_repo() {
         .arg("--depth=1")
         .arg(toolstate_repo())
         .arg(TOOLSTATE_DIR)
+        .command
         .status();
     let success = match status {
         Ok(s) => s.success(),
@@ -337,7 +343,8 @@ fn checkout_toolstate_repo() {
 /// Sets up config and authentication for modifying the toolstate repo.
 fn prepare_toolstate_config(token: &str) {
     fn git_config(key: &str, value: &str) {
-        let status = helpers::git(None).arg("config").arg("--global").arg(key).arg(value).status();
+        let status =
+            helpers::git(None).arg("config").arg("--global").arg(key).arg(value).command.status();
         let success = match status {
             Ok(s) => s.success(),
             Err(_) => false,
@@ -406,6 +413,7 @@ fn commit_toolstate_change(current_toolstate: &ToolstateData) {
             .arg("-a")
             .arg("-m")
             .arg(&message)
+            .command
             .status());
         if !status.success() {
             success = true;
@@ -416,6 +424,7 @@ fn commit_toolstate_change(current_toolstate: &ToolstateData) {
             .arg("push")
             .arg("origin")
             .arg("master")
+            .command
             .status());
         // If we successfully push, exit.
         if status.success() {
@@ -428,12 +437,14 @@ fn commit_toolstate_change(current_toolstate: &ToolstateData) {
             .arg("fetch")
             .arg("origin")
             .arg("master")
+            .command
             .status());
         assert!(status.success());
         let status = t!(helpers::git(Some(Path::new(TOOLSTATE_DIR)))
             .arg("reset")
             .arg("--hard")
             .arg("origin/master")
+            .command
             .status());
         assert!(status.success());
     }
@@ -449,7 +460,7 @@ fn commit_toolstate_change(current_toolstate: &ToolstateData) {
 /// `publish_toolstate.py` script if the PR passes all tests and is merged to
 /// master.
 fn publish_test_results(current_toolstate: &ToolstateData) {
-    let commit = t!(helpers::git(None).arg("rev-parse").arg("HEAD").output());
+    let commit = t!(helpers::git(None).arg("rev-parse").arg("HEAD").command.output());
     let commit = t!(String::from_utf8(commit.stdout));
 
     let toolstate_serialized = t!(serde_json::to_string(&current_toolstate));
diff --git a/src/bootstrap/src/core/builder.rs b/src/bootstrap/src/core/builder.rs
index 58d6e7a58e3..4da912994c3 100644
--- a/src/bootstrap/src/core/builder.rs
+++ b/src/bootstrap/src/core/builder.rs
@@ -8,7 +8,6 @@ use std::fs;
 use std::hash::Hash;
 use std::ops::Deref;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 use std::time::{Duration, Instant};
 
 use crate::core::build_steps::tool::{self, SourceType};
@@ -20,7 +19,7 @@ use crate::core::config::{DryRun, SplitDebuginfo, TargetSelection};
 use crate::prepare_behaviour_dump_dir;
 use crate::utils::cache::Cache;
 use crate::utils::helpers::{self, add_dylib_path, add_link_lib_path, exe, linker_args};
-use crate::utils::helpers::{check_cfg_arg, libdir, linker_flags, output, t, LldThreads};
+use crate::utils::helpers::{check_cfg_arg, libdir, linker_flags, t, LldThreads};
 use crate::EXTRA_CHECK_CFGS;
 use crate::{Build, CLang, Crate, DocTests, GitRepo, Mode};
 
@@ -1919,7 +1918,9 @@ impl<'a> Builder<'a> {
         // platform-specific environment variable as a workaround.
         if mode == Mode::ToolRustc || mode == Mode::Codegen {
             if let Some(llvm_config) = self.llvm_config(target) {
-                let llvm_libdir = output(Command::new(llvm_config).arg("--libdir"));
+                let llvm_libdir = self
+                    .run(BootstrapCommand::new(llvm_config).capture_stdout().arg("--libdir"))
+                    .stdout();
                 add_link_lib_path(vec![llvm_libdir.trim().into()], &mut cargo);
             }
         }
@@ -2398,6 +2399,10 @@ impl Cargo {
         cargo
     }
 
+    pub fn into_cmd(self) -> BootstrapCommand {
+        self.into()
+    }
+
     /// Same as `Cargo::new` except this one doesn't configure the linker with `Cargo::configure_linker`
     pub fn new_for_mir_opt_tests(
         builder: &Builder<'_>,
@@ -2622,9 +2627,3 @@ impl From<Cargo> for BootstrapCommand {
         cargo.command
     }
 }
-
-impl From<Cargo> for Command {
-    fn from(cargo: Cargo) -> Command {
-        BootstrapCommand::from(cargo).command
-    }
-}
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 948f97e746f..10ac6c93e9a 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -1259,6 +1259,7 @@ impl Config {
         cmd.arg("rev-parse").arg("--show-cdup");
         // Discard stderr because we expect this to fail when building from a tarball.
         let output = cmd
+            .command
             .stderr(std::process::Stdio::null())
             .output()
             .ok()
@@ -2141,7 +2142,7 @@ impl Config {
 
         let mut git = helpers::git(Some(&self.src));
         git.arg("show").arg(format!("{commit}:{}", file.to_str().unwrap()));
-        output(&mut git)
+        output(&mut git.command)
     }
 
     /// Bootstrap embeds a version number into the name of shared libraries it uploads in CI.
@@ -2445,8 +2446,9 @@ impl Config {
         };
 
         // Handle running from a directory other than the top level
-        let top_level =
-            output(helpers::git(Some(&self.src)).args(["rev-parse", "--show-toplevel"]));
+        let top_level = output(
+            &mut helpers::git(Some(&self.src)).args(["rev-parse", "--show-toplevel"]).command,
+        );
         let top_level = top_level.trim_end();
         let compiler = format!("{top_level}/compiler/");
         let library = format!("{top_level}/library/");
@@ -2454,10 +2456,11 @@ impl Config {
         // Look for a version to compare to based on the current commit.
         // Only commits merged by bors will have CI artifacts.
         let merge_base = output(
-            helpers::git(Some(&self.src))
+            &mut helpers::git(Some(&self.src))
                 .arg("rev-list")
                 .arg(format!("--author={}", self.stage0_metadata.config.git_merge_commit_email))
-                .args(["-n1", "--first-parent", "HEAD"]),
+                .args(["-n1", "--first-parent", "HEAD"])
+                .command,
         );
         let commit = merge_base.trim_end();
         if commit.is_empty() {
@@ -2471,6 +2474,7 @@ impl Config {
         // Warn if there were changes to the compiler or standard library since the ancestor commit.
         let has_changes = !t!(helpers::git(Some(&self.src))
             .args(["diff-index", "--quiet", commit, "--", &compiler, &library])
+            .command
             .status())
         .success();
         if has_changes {
@@ -2542,17 +2546,19 @@ impl Config {
         if_unchanged: bool,
     ) -> Option<String> {
         // Handle running from a directory other than the top level
-        let top_level =
-            output(helpers::git(Some(&self.src)).args(["rev-parse", "--show-toplevel"]));
+        let top_level = output(
+            &mut helpers::git(Some(&self.src)).args(["rev-parse", "--show-toplevel"]).command,
+        );
         let top_level = top_level.trim_end();
 
         // Look for a version to compare to based on the current commit.
         // Only commits merged by bors will have CI artifacts.
         let merge_base = output(
-            helpers::git(Some(&self.src))
+            &mut helpers::git(Some(&self.src))
                 .arg("rev-list")
                 .arg(format!("--author={}", self.stage0_metadata.config.git_merge_commit_email))
-                .args(["-n1", "--first-parent", "HEAD"]),
+                .args(["-n1", "--first-parent", "HEAD"])
+                .command,
         );
         let commit = merge_base.trim_end();
         if commit.is_empty() {
@@ -2571,7 +2577,7 @@ impl Config {
             git.arg(format!("{top_level}/{path}"));
         }
 
-        let has_changes = !t!(git.status()).success();
+        let has_changes = !t!(git.command.status()).success();
         if has_changes {
             if if_unchanged {
                 if self.verbose > 0 {
diff --git a/src/bootstrap/src/core/metadata.rs b/src/bootstrap/src/core/metadata.rs
index 220eb5ba126..49d17107125 100644
--- a/src/bootstrap/src/core/metadata.rs
+++ b/src/bootstrap/src/core/metadata.rs
@@ -1,9 +1,8 @@
 use std::path::PathBuf;
-use std::process::Command;
 
 use serde_derive::Deserialize;
 
-use crate::utils::helpers::output;
+use crate::utils::exec::BootstrapCommand;
 use crate::{t, Build, Crate};
 
 /// For more information, see the output of
@@ -71,7 +70,7 @@ pub fn build(build: &mut Build) {
 /// particular crate (e.g., `x build sysroot` to build library/sysroot).
 fn workspace_members(build: &Build) -> Vec<Package> {
     let collect_metadata = |manifest_path| {
-        let mut cargo = Command::new(&build.initial_cargo);
+        let mut cargo = BootstrapCommand::new(&build.initial_cargo);
         cargo
             // Will read the libstd Cargo.toml
             // which uses the unstable `public-dependency` feature.
@@ -82,7 +81,7 @@ fn workspace_members(build: &Build) -> Vec<Package> {
             .arg("--no-deps")
             .arg("--manifest-path")
             .arg(build.src.join(manifest_path));
-        let metadata_output = output(&mut cargo);
+        let metadata_output = build.run(cargo.capture_stdout().run_always()).stdout();
         let Output { packages, .. } = t!(serde_json::from_str(&metadata_output));
         packages
     };
diff --git a/src/bootstrap/src/core/sanity.rs b/src/bootstrap/src/core/sanity.rs
index 5a0be2948a1..78862ccb8cd 100644
--- a/src/bootstrap/src/core/sanity.rs
+++ b/src/bootstrap/src/core/sanity.rs
@@ -13,7 +13,6 @@ use std::env;
 use std::ffi::{OsStr, OsString};
 use std::fs;
 use std::path::PathBuf;
-use std::process::Command;
 
 #[cfg(not(feature = "bootstrap-self-test"))]
 use crate::builder::Builder;
@@ -24,7 +23,7 @@ use std::collections::HashSet;
 
 use crate::builder::Kind;
 use crate::core::config::Target;
-use crate::utils::helpers::output;
+use crate::utils::exec::BootstrapCommand;
 use crate::Build;
 
 pub struct Finder {
@@ -209,11 +208,14 @@ than building it.
         .or_else(|| cmd_finder.maybe_have("reuse"));
 
     #[cfg(not(feature = "bootstrap-self-test"))]
-    let stage0_supported_target_list: HashSet<String> =
-        output(Command::new(&build.config.initial_rustc).args(["--print", "target-list"]))
-            .lines()
-            .map(|s| s.to_string())
-            .collect();
+    let stage0_supported_target_list: HashSet<String> = crate::utils::helpers::output(
+        &mut BootstrapCommand::new(&build.config.initial_rustc)
+            .args(["--print", "target-list"])
+            .command,
+    )
+    .lines()
+    .map(|s| s.to_string())
+    .collect();
 
     // We're gonna build some custom C code here and there, host triples
     // also build some C++ shims for LLVM so we need a C++ compiler.
@@ -352,7 +354,8 @@ than building it.
             // There are three builds of cmake on windows: MSVC, MinGW, and
             // Cygwin. The Cygwin build does not have generators for Visual
             // Studio, so detect that here and error.
-            let out = output(Command::new("cmake").arg("--help"));
+            let out =
+                build.run(BootstrapCommand::new("cmake").capture_stdout().arg("--help")).stdout();
             if !out.contains("Visual Studio") {
                 panic!(
                     "
diff --git a/src/bootstrap/src/lib.rs b/src/bootstrap/src/lib.rs
index c12449fdc4a..ffdd9bc885a 100644
--- a/src/bootstrap/src/lib.rs
+++ b/src/bootstrap/src/lib.rs
@@ -30,7 +30,6 @@ use std::time::SystemTime;
 
 use build_helper::ci::{gha, CiEnv};
 use build_helper::exit;
-use build_helper::util::fail;
 use filetime::FileTime;
 use sha2::digest::Digest;
 use termcolor::{ColorChoice, StandardStream, WriteColor};
@@ -42,7 +41,7 @@ use crate::core::builder::Kind;
 use crate::core::config::{flags, LldMode};
 use crate::core::config::{DryRun, Target};
 use crate::core::config::{LlvmLibunwind, TargetSelection};
-use crate::utils::exec::{BehaviorOnFailure, BootstrapCommand, CommandOutput, OutputMode};
+use crate::utils::exec::{BehaviorOnFailure, BootstrapCommand, CommandOutput};
 use crate::utils::helpers::{self, dir_is_empty, exe, libdir, mtime, output, symlink_dir};
 
 mod core;
@@ -494,11 +493,12 @@ impl Build {
         let submodule_git = || helpers::git(Some(&absolute_path));
 
         // Determine commit checked out in submodule.
-        let checked_out_hash = output(submodule_git().args(["rev-parse", "HEAD"]));
+        let checked_out_hash = output(&mut submodule_git().args(["rev-parse", "HEAD"]).command);
         let checked_out_hash = checked_out_hash.trim_end();
         // Determine commit that the submodule *should* have.
-        let recorded =
-            output(helpers::git(Some(&self.src)).args(["ls-tree", "HEAD"]).arg(relative_path));
+        let recorded = output(
+            &mut helpers::git(Some(&self.src)).args(["ls-tree", "HEAD"]).arg(relative_path).command,
+        );
         let actual_hash = recorded
             .split_whitespace()
             .nth(2)
@@ -521,6 +521,7 @@ impl Build {
             let current_branch = {
                 let output = helpers::git(Some(&self.src))
                     .args(["symbolic-ref", "--short", "HEAD"])
+                    .command
                     .stderr(Stdio::inherit())
                     .output();
                 let output = t!(output);
@@ -546,17 +547,14 @@ impl Build {
             git
         };
         // NOTE: doesn't use `try_run` because this shouldn't print an error if it fails.
-        if !update(true).status().map_or(false, |status| status.success()) {
+        if !update(true).command.status().map_or(false, |status| status.success()) {
             self.run(update(false));
         }
 
         // Save any local changes, but avoid running `git stash pop` if there are none (since it will exit with an error).
         // diff-index reports the modifications through the exit status
         let has_local_modifications = self
-            .run(
-                BootstrapCommand::from(submodule_git().args(["diff-index", "--quiet", "HEAD"]))
-                    .allow_failure(),
-            )
+            .run(submodule_git().allow_failure().args(["diff-index", "--quiet", "HEAD"]))
             .is_failure();
         if has_local_modifications {
             self.run(submodule_git().args(["stash", "push"]));
@@ -577,12 +575,15 @@ impl Build {
         if !self.config.submodules(self.rust_info()) {
             return;
         }
-        let output = output(
-            helpers::git(Some(&self.src))
-                .args(["config", "--file"])
-                .arg(self.config.src.join(".gitmodules"))
-                .args(["--get-regexp", "path"]),
-        );
+        let output = self
+            .run(
+                helpers::git(Some(&self.src))
+                    .capture()
+                    .args(["config", "--file"])
+                    .arg(self.config.src.join(".gitmodules"))
+                    .args(["--get-regexp", "path"]),
+            )
+            .stdout();
         for line in output.lines() {
             // Look for `submodule.$name.path = $path`
             // Sample output: `submodule.src/rust-installer.path src/tools/rust-installer`
@@ -859,14 +860,16 @@ impl Build {
         if let Some(s) = target_config.and_then(|c| c.llvm_filecheck.as_ref()) {
             s.to_path_buf()
         } else if let Some(s) = target_config.and_then(|c| c.llvm_config.as_ref()) {
-            let llvm_bindir = output(Command::new(s).arg("--bindir"));
+            let llvm_bindir =
+                self.run(BootstrapCommand::new(s).capture_stdout().arg("--bindir")).stdout();
             let filecheck = Path::new(llvm_bindir.trim()).join(exe("FileCheck", target));
             if filecheck.exists() {
                 filecheck
             } else {
                 // On Fedora the system LLVM installs FileCheck in the
                 // llvm subdirectory of the libdir.
-                let llvm_libdir = output(Command::new(s).arg("--libdir"));
+                let llvm_libdir =
+                    self.run(BootstrapCommand::new(s).capture_stdout().arg("--libdir")).stdout();
                 let lib_filecheck =
                     Path::new(llvm_libdir.trim()).join("llvm").join(exe("FileCheck", target));
                 if lib_filecheck.exists() {
@@ -932,66 +935,79 @@ impl Build {
 
     /// Execute a command and return its output.
     /// This method should be used for all command executions in bootstrap.
-    fn run<C: Into<BootstrapCommand>>(&self, command: C) -> CommandOutput {
-        if self.config.dry_run() {
+    fn run<C: AsMut<BootstrapCommand>>(&self, mut command: C) -> CommandOutput {
+        let command = command.as_mut();
+        if self.config.dry_run() && !command.run_always {
             return CommandOutput::default();
         }
 
-        let mut command = command.into();
-
         self.verbose(|| println!("running: {command:?}"));
 
-        let output_mode = command.output_mode.unwrap_or_else(|| match self.is_verbose() {
-            true => OutputMode::All,
-            false => OutputMode::OnlyOutput,
-        });
-        let (output, print_error): (io::Result<CommandOutput>, bool) = match output_mode {
-            mode @ (OutputMode::All | OutputMode::OnlyOutput) => (
-                command.command.status().map(|status| status.into()),
-                matches!(mode, OutputMode::All),
-            ),
-            OutputMode::OnlyOnFailure => (command.command.output().map(|o| o.into()), true),
-        };
-
-        let output = match output {
-            Ok(output) => output,
-            Err(e) => fail(&format!("failed to execute command: {:?}\nerror: {}", command, e)),
-        };
-        if !output.is_success() {
-            if print_error {
-                println!(
-                    "\n\nCommand did not execute successfully.\
-                \nExpected success, got: {}",
-                    output.status(),
-                );
-
-                if !self.is_verbose() {
-                    println!("Add `-v` to see more details.\n");
+        command.command.stdout(command.stdout.stdio());
+        command.command.stderr(command.stderr.stdio());
+
+        let output = command.command.output();
+
+        use std::fmt::Write;
+
+        let mut message = String::new();
+        let output: CommandOutput = match output {
+            // Command has succeeded
+            Ok(output) if output.status.success() => output.into(),
+            // Command has started, but then it failed
+            Ok(output) => {
+                writeln!(
+                    message,
+                    "\n\nCommand {command:?} did not execute successfully.\
+            \nExpected success, got: {}",
+                    output.status,
+                )
+                .unwrap();
+
+                let output: CommandOutput = output.into();
+
+                // If the output mode is OutputMode::Capture, we can now print the output.
+                // If it is OutputMode::Print, then the output has already been printed to
+                // stdout/stderr, and we thus don't have anything captured to print anyway.
+                if command.stdout.captures() {
+                    writeln!(message, "\nSTDOUT ----\n{}", output.stdout().trim()).unwrap();
                 }
-
-                self.verbose(|| {
-                    println!(
-                        "\nSTDOUT ----\n{}\n\
-                    STDERR ----\n{}\n",
-                        output.stdout(),
-                        output.stderr(),
-                    )
-                });
+                if command.stderr.captures() {
+                    writeln!(message, "\nSTDERR ----\n{}", output.stderr().trim()).unwrap();
+                }
+                output
             }
-
+            // The command did not even start
+            Err(e) => {
+                writeln!(
+                    message,
+                    "\n\nCommand {command:?} did not execute successfully.\
+            \nIt was not possible to execute the command: {e:?}"
+                )
+                .unwrap();
+                CommandOutput::did_not_start()
+            }
+        };
+        if !output.is_success() {
             match command.failure_behavior {
                 BehaviorOnFailure::DelayFail => {
                     if self.fail_fast {
+                        println!("{message}");
                         exit!(1);
                     }
 
                     let mut failures = self.delayed_failures.borrow_mut();
-                    failures.push(format!("{command:?}"));
+                    failures.push(message);
                 }
                 BehaviorOnFailure::Exit => {
+                    println!("{message}");
                     exit!(1);
                 }
-                BehaviorOnFailure::Ignore => {}
+                BehaviorOnFailure::Ignore => {
+                    // If failures are allowed, either the error has been printed already
+                    // (OutputMode::Print) or the user used a capture output mode and wants to
+                    // handle the error output on their own.
+                }
             }
         }
         output
@@ -1480,14 +1496,18 @@ impl Build {
             // Figure out how many merge commits happened since we branched off master.
             // That's our beta number!
             // (Note that we use a `..` range, not the `...` symmetric difference.)
-            output(
-                helpers::git(Some(&self.src)).arg("rev-list").arg("--count").arg("--merges").arg(
-                    format!(
+            self.run(
+                helpers::git(Some(&self.src))
+                    .capture()
+                    .arg("rev-list")
+                    .arg("--count")
+                    .arg("--merges")
+                    .arg(format!(
                         "refs/remotes/origin/{}..HEAD",
                         self.config.stage0_metadata.config.nightly_branch
-                    ),
-                ),
+                    )),
             )
+            .stdout()
         });
         let n = count.trim().parse().unwrap();
         self.prerelease_version.set(Some(n));
@@ -1914,6 +1934,7 @@ fn envify(s: &str) -> String {
 pub fn generate_smart_stamp_hash(dir: &Path, additional_input: &str) -> String {
     let diff = helpers::git(Some(dir))
         .arg("diff")
+        .command
         .output()
         .map(|o| String::from_utf8(o.stdout).unwrap_or_default())
         .unwrap_or_default();
@@ -1923,6 +1944,7 @@ pub fn generate_smart_stamp_hash(dir: &Path, additional_input: &str) -> String {
         .arg("--porcelain")
         .arg("-z")
         .arg("--untracked-files=normal")
+        .command
         .output()
         .map(|o| String::from_utf8(o.stdout).unwrap_or_default())
         .unwrap_or_default();
diff --git a/src/bootstrap/src/utils/cc_detect.rs b/src/bootstrap/src/utils/cc_detect.rs
index 540b8671333..b80df545202 100644
--- a/src/bootstrap/src/utils/cc_detect.rs
+++ b/src/bootstrap/src/utils/cc_detect.rs
@@ -23,11 +23,10 @@
 
 use std::collections::HashSet;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 use std::{env, iter};
 
 use crate::core::config::TargetSelection;
-use crate::utils::helpers::output;
+use crate::utils::exec::BootstrapCommand;
 use crate::{Build, CLang, GitRepo};
 
 // The `cc` crate doesn't provide a way to obtain a path to the detected archiver,
@@ -183,14 +182,15 @@ fn default_compiler(
                 return None;
             }
 
-            let output = output(c.to_command().arg("--version"));
+            let cmd = BootstrapCommand::from(c.to_command());
+            let output = build.run(cmd.capture_stdout().arg("--version")).stdout();
             let i = output.find(" 4.")?;
             match output[i + 3..].chars().next().unwrap() {
                 '0'..='6' => {}
                 _ => return None,
             }
             let alternative = format!("e{gnu_compiler}");
-            if Command::new(&alternative).output().is_ok() {
+            if build.run(BootstrapCommand::new(&alternative).capture()).is_success() {
                 Some(PathBuf::from(alternative))
             } else {
                 None
diff --git a/src/bootstrap/src/utils/channel.rs b/src/bootstrap/src/utils/channel.rs
index ce82c52f049..2ca86bdb0ed 100644
--- a/src/bootstrap/src/utils/channel.rs
+++ b/src/bootstrap/src/utils/channel.rs
@@ -45,7 +45,7 @@ impl GitInfo {
         }
 
         // Make sure git commands work
-        match helpers::git(Some(dir)).arg("rev-parse").output() {
+        match helpers::git(Some(dir)).arg("rev-parse").command.output() {
             Ok(ref out) if out.status.success() => {}
             _ => return GitInfo::Absent,
         }
@@ -58,15 +58,17 @@ impl GitInfo {
 
         // Ok, let's scrape some info
         let ver_date = output(
-            helpers::git(Some(dir))
+            &mut helpers::git(Some(dir))
                 .arg("log")
                 .arg("-1")
                 .arg("--date=short")
-                .arg("--pretty=format:%cd"),
+                .arg("--pretty=format:%cd")
+                .command,
+        );
+        let ver_hash = output(&mut helpers::git(Some(dir)).arg("rev-parse").arg("HEAD").command);
+        let short_ver_hash = output(
+            &mut helpers::git(Some(dir)).arg("rev-parse").arg("--short=9").arg("HEAD").command,
         );
-        let ver_hash = output(helpers::git(Some(dir)).arg("rev-parse").arg("HEAD"));
-        let short_ver_hash =
-            output(helpers::git(Some(dir)).arg("rev-parse").arg("--short=9").arg("HEAD"));
         GitInfo::Present(Some(Info {
             commit_date: ver_date.trim().to_string(),
             sha: ver_hash.trim().to_string(),
diff --git a/src/bootstrap/src/utils/exec.rs b/src/bootstrap/src/utils/exec.rs
index 8bcb2301f1a..086d10c6351 100644
--- a/src/bootstrap/src/utils/exec.rs
+++ b/src/bootstrap/src/utils/exec.rs
@@ -1,6 +1,6 @@
 use std::ffi::OsStr;
 use std::path::Path;
-use std::process::{Command, CommandArgs, CommandEnvs, ExitStatus, Output};
+use std::process::{Command, CommandArgs, CommandEnvs, ExitStatus, Output, Stdio};
 
 /// What should be done when the command fails.
 #[derive(Debug, Copy, Clone)]
@@ -13,16 +13,30 @@ pub enum BehaviorOnFailure {
     Ignore,
 }
 
-/// How should the output of the command be handled.
+/// How should the output of a specific stream of the command (stdout/stderr) be handled
+/// (whether it should be captured or printed).
 #[derive(Debug, Copy, Clone)]
 pub enum OutputMode {
-    /// Print both the output (by inheriting stdout/stderr) and also the command itself, if it
-    /// fails.
-    All,
-    /// Print the output (by inheriting stdout/stderr).
-    OnlyOutput,
-    /// Suppress the output if the command succeeds, otherwise print the output.
-    OnlyOnFailure,
+    /// Prints the stream by inheriting it from the bootstrap process.
+    Print,
+    /// Captures the stream into memory.
+    Capture,
+}
+
+impl OutputMode {
+    pub fn captures(&self) -> bool {
+        match self {
+            OutputMode::Print => false,
+            OutputMode::Capture => true,
+        }
+    }
+
+    pub fn stdio(&self) -> Stdio {
+        match self {
+            OutputMode::Print => Stdio::inherit(),
+            OutputMode::Capture => Stdio::piped(),
+        }
+    }
 }
 
 /// Wrapper around `std::process::Command`.
@@ -31,10 +45,10 @@ pub enum OutputMode {
 /// If you want to allow failures, use [allow_failure].
 /// If you want to delay failures until the end of bootstrap, use [delay_failure].
 ///
-/// By default, the command will print its stdout/stderr to stdout/stderr of bootstrap
-/// ([OutputMode::OnlyOutput]). If bootstrap uses verbose mode, then it will also print the
-/// command itself in case of failure ([OutputMode::All]).
-/// If you want to handle the output programmatically, use `output_mode(OutputMode::OnlyOnFailure)`.
+/// By default, the command will print its stdout/stderr to stdout/stderr of bootstrap ([OutputMode::Print]).
+/// If you want to handle the output programmatically, use [BootstrapCommand::capture].
+///
+/// Bootstrap will print a debug log to stdout if the command fails and failure is not allowed.
 ///
 /// [allow_failure]: BootstrapCommand::allow_failure
 /// [delay_failure]: BootstrapCommand::delay_failure
@@ -42,7 +56,10 @@ pub enum OutputMode {
 pub struct BootstrapCommand {
     pub command: Command,
     pub failure_behavior: BehaviorOnFailure,
-    pub output_mode: Option<OutputMode>,
+    pub stdout: OutputMode,
+    pub stderr: OutputMode,
+    // Run the command even during dry run
+    pub run_always: bool,
 }
 
 impl BootstrapCommand {
@@ -103,95 +120,110 @@ impl BootstrapCommand {
         Self { failure_behavior: BehaviorOnFailure::Ignore, ..self }
     }
 
-    /// Do not print the output of the command, unless it fails.
-    pub fn quiet(self) -> Self {
-        self.output_mode(OutputMode::OnlyOnFailure)
+    pub fn run_always(&mut self) -> &mut Self {
+        self.run_always = true;
+        self
     }
 
-    pub fn output_mode(self, output_mode: OutputMode) -> Self {
-        Self { output_mode: Some(output_mode), ..self }
+    /// Capture all output of the command, do not print it.
+    pub fn capture(self) -> Self {
+        Self { stdout: OutputMode::Capture, stderr: OutputMode::Capture, ..self }
     }
-}
 
-/// This implementation is temporary, until all `Command` invocations are migrated to
-/// `BootstrapCommand`.
-impl<'a> From<&'a mut Command> for BootstrapCommand {
-    fn from(command: &'a mut Command) -> Self {
-        // This is essentially a manual `Command::clone`
-        let mut cmd = Command::new(command.get_program());
-        if let Some(dir) = command.get_current_dir() {
-            cmd.current_dir(dir);
-        }
-        cmd.args(command.get_args());
-        for (key, value) in command.get_envs() {
-            match value {
-                Some(value) => {
-                    cmd.env(key, value);
-                }
-                None => {
-                    cmd.env_remove(key);
-                }
-            }
-        }
-
-        cmd.into()
+    /// Capture stdout of the command, do not print it.
+    pub fn capture_stdout(self) -> Self {
+        Self { stdout: OutputMode::Capture, ..self }
     }
 }
 
-/// This implementation is temporary, until all `Command` invocations are migrated to
-/// `BootstrapCommand`.
-impl<'a> From<&'a mut BootstrapCommand> for BootstrapCommand {
-    fn from(command: &'a mut BootstrapCommand) -> Self {
-        BootstrapCommand::from(&mut command.command)
+/// This implementation exists to make it possible to pass both [BootstrapCommand] and
+/// `&mut BootstrapCommand` to `Build.run()`.
+impl AsMut<BootstrapCommand> for BootstrapCommand {
+    fn as_mut(&mut self) -> &mut BootstrapCommand {
+        self
     }
 }
 
 impl From<Command> for BootstrapCommand {
     fn from(command: Command) -> Self {
-        Self { command, failure_behavior: BehaviorOnFailure::Exit, output_mode: None }
+        Self {
+            command,
+            failure_behavior: BehaviorOnFailure::Exit,
+            stdout: OutputMode::Print,
+            stderr: OutputMode::Print,
+            run_always: false,
+        }
     }
 }
 
+/// Represents the current status of `BootstrapCommand`.
+enum CommandStatus {
+    /// The command has started and finished with some status.
+    Finished(ExitStatus),
+    /// It was not even possible to start the command.
+    DidNotStart,
+}
+
 /// Represents the output of an executed process.
 #[allow(unused)]
-pub struct CommandOutput(Output);
+pub struct CommandOutput {
+    status: CommandStatus,
+    stdout: Vec<u8>,
+    stderr: Vec<u8>,
+}
 
 impl CommandOutput {
+    pub fn did_not_start() -> Self {
+        Self { status: CommandStatus::DidNotStart, stdout: vec![], stderr: vec![] }
+    }
+
     pub fn is_success(&self) -> bool {
-        self.0.status.success()
+        match self.status {
+            CommandStatus::Finished(status) => status.success(),
+            CommandStatus::DidNotStart => false,
+        }
     }
 
     pub fn is_failure(&self) -> bool {
         !self.is_success()
     }
 
-    pub fn status(&self) -> ExitStatus {
-        self.0.status
+    pub fn status(&self) -> Option<ExitStatus> {
+        match self.status {
+            CommandStatus::Finished(status) => Some(status),
+            CommandStatus::DidNotStart => None,
+        }
     }
 
     pub fn stdout(&self) -> String {
-        String::from_utf8(self.0.stdout.clone()).expect("Cannot parse process stdout as UTF-8")
+        String::from_utf8(self.stdout.clone()).expect("Cannot parse process stdout as UTF-8")
+    }
+
+    pub fn stdout_if_ok(&self) -> Option<String> {
+        if self.is_success() { Some(self.stdout()) } else { None }
     }
 
     pub fn stderr(&self) -> String {
-        String::from_utf8(self.0.stderr.clone()).expect("Cannot parse process stderr as UTF-8")
+        String::from_utf8(self.stderr.clone()).expect("Cannot parse process stderr as UTF-8")
     }
 }
 
 impl Default for CommandOutput {
     fn default() -> Self {
-        Self(Output { status: Default::default(), stdout: vec![], stderr: vec![] })
+        Self {
+            status: CommandStatus::Finished(ExitStatus::default()),
+            stdout: vec![],
+            stderr: vec![],
+        }
     }
 }
 
 impl From<Output> for CommandOutput {
     fn from(output: Output) -> Self {
-        Self(output)
-    }
-}
-
-impl From<ExitStatus> for CommandOutput {
-    fn from(status: ExitStatus) -> Self {
-        Self(Output { status, stdout: vec![], stderr: vec![] })
+        Self {
+            status: CommandStatus::Finished(output.status),
+            stdout: output.stdout,
+            stderr: output.stderr,
+        }
     }
 }
diff --git a/src/bootstrap/src/utils/helpers.rs b/src/bootstrap/src/utils/helpers.rs
index adf18c0ace1..2575b7939b4 100644
--- a/src/bootstrap/src/utils/helpers.rs
+++ b/src/bootstrap/src/utils/helpers.rs
@@ -360,7 +360,7 @@ pub fn get_clang_cl_resource_dir(clang_cl_path: &str) -> PathBuf {
 /// Returns a flag that configures LLD to use only a single thread.
 /// If we use an external LLD, we need to find out which version is it to know which flag should we
 /// pass to it (LLD older than version 10 had a different flag).
-fn lld_flag_no_threads(lld_mode: LldMode, is_windows: bool) -> &'static str {
+fn lld_flag_no_threads(builder: &Builder<'_>, lld_mode: LldMode, is_windows: bool) -> &'static str {
     static LLD_NO_THREADS: OnceLock<(&'static str, &'static str)> = OnceLock::new();
 
     let new_flags = ("/threads:1", "--threads=1");
@@ -369,7 +369,9 @@ fn lld_flag_no_threads(lld_mode: LldMode, is_windows: bool) -> &'static str {
     let (windows_flag, other_flag) = LLD_NO_THREADS.get_or_init(|| {
         let newer_version = match lld_mode {
             LldMode::External => {
-                let out = output(Command::new("lld").arg("-flavor").arg("ld").arg("--version"));
+                let mut cmd = BootstrapCommand::new("lld").capture_stdout();
+                cmd.arg("-flavor").arg("ld").arg("--version");
+                let out = builder.run(cmd).stdout();
                 match (out.find(char::is_numeric), out.find('.')) {
                     (Some(b), Some(e)) => out.as_str()[b..e].parse::<i32>().ok().unwrap_or(14) > 10,
                     _ => true,
@@ -431,7 +433,7 @@ pub fn linker_flags(
         if matches!(lld_threads, LldThreads::No) {
             args.push(format!(
                 "-Clink-arg=-Wl,{}",
-                lld_flag_no_threads(builder.config.lld_mode, target.is_windows())
+                lld_flag_no_threads(builder, builder.config.lld_mode, target.is_windows())
             ));
         }
     }
@@ -492,14 +494,15 @@ pub fn check_cfg_arg(name: &str, values: Option<&[&str]>) -> String {
     format!("--check-cfg=cfg({name}{next})")
 }
 
-/// Prepares `Command` that runs git inside the source directory if given.
+/// Prepares `BootstrapCommand` that runs git inside the source directory if given.
 ///
 /// Whenever a git invocation is needed, this function should be preferred over
-/// manually building a git `Command`. This approach allows us to manage bootstrap-specific
-/// needs/hacks from a single source, rather than applying them on next to every `Command::new("git")`,
-/// which is painful to ensure that the required change is applied on each one of them correctly.
-pub fn git(source_dir: Option<&Path>) -> Command {
-    let mut git = Command::new("git");
+/// manually building a git `BootstrapCommand`. This approach allows us to manage
+/// bootstrap-specific needs/hacks from a single source, rather than applying them on next to every
+/// `BootstrapCommand::new("git")`, which is painful to ensure that the required change is applied
+/// on each one of them correctly.
+pub fn git(source_dir: Option<&Path>) -> BootstrapCommand {
+    let mut git = BootstrapCommand::new("git");
 
     if let Some(source_dir) = source_dir {
         git.current_dir(source_dir);
diff --git a/src/bootstrap/src/utils/tarball.rs b/src/bootstrap/src/utils/tarball.rs
index 3c15bb296f3..1a35dc1fd38 100644
--- a/src/bootstrap/src/utils/tarball.rs
+++ b/src/bootstrap/src/utils/tarball.rs
@@ -370,7 +370,11 @@ impl<'a> Tarball<'a> {
         if self.builder.rust_info().is_managed_git_subrepository() {
             // %ct means committer date
             let timestamp = helpers::output(
-                helpers::git(Some(&self.builder.src)).arg("log").arg("-1").arg("--format=%ct"),
+                &mut helpers::git(Some(&self.builder.src))
+                    .arg("log")
+                    .arg("-1")
+                    .arg("--format=%ct")
+                    .command,
             );
             cmd.args(["--override-file-mtime", timestamp.trim()]);
         }
diff --git a/src/librustdoc/clean/types.rs b/src/librustdoc/clean/types.rs
index 3b1a8830e1c..fe01d17b08a 100644
--- a/src/librustdoc/clean/types.rs
+++ b/src/librustdoc/clean/types.rs
@@ -1286,7 +1286,7 @@ impl GenericBound {
     }
 }
 
-#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Hash)]
 pub(crate) struct Lifetime(pub Symbol);
 
 impl Lifetime {
diff --git a/src/librustdoc/json/conversions.rs b/src/librustdoc/json/conversions.rs
index b965ab019cc..5111e363c52 100644
--- a/src/librustdoc/json/conversions.rs
+++ b/src/librustdoc/json/conversions.rs
@@ -10,6 +10,7 @@ use rustc_ast::ast;
 use rustc_attr::DeprecatedSince;
 use rustc_hir::{def::CtorKind, def::DefKind, def_id::DefId};
 use rustc_metadata::rendered_const;
+use rustc_middle::bug;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_span::symbol::sym;
 use rustc_span::{Pos, Symbol};
@@ -512,9 +513,15 @@ impl FromWithTcx<clean::WherePredicate> for WherePredicate {
                     })
                     .collect(),
             },
-            RegionPredicate { lifetime, bounds } => WherePredicate::RegionPredicate {
+            RegionPredicate { lifetime, bounds } => WherePredicate::LifetimePredicate {
                 lifetime: convert_lifetime(lifetime),
-                bounds: bounds.into_tcx(tcx),
+                outlives: bounds
+                    .iter()
+                    .map(|bound| match bound {
+                        clean::GenericBound::Outlives(lt) => convert_lifetime(*lt),
+                        _ => bug!("found non-outlives-bound on lifetime predicate"),
+                    })
+                    .collect(),
             },
             EqPredicate { lhs, rhs } => {
                 WherePredicate::EqPredicate { lhs: lhs.into_tcx(tcx), rhs: rhs.into_tcx(tcx) }
diff --git a/src/librustdoc/passes/lint/bare_urls.rs b/src/librustdoc/passes/lint/bare_urls.rs
index 4b2d3092837..a4ba718789c 100644
--- a/src/librustdoc/passes/lint/bare_urls.rs
+++ b/src/librustdoc/passes/lint/bare_urls.rs
@@ -19,22 +19,22 @@ pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item) {
     };
     let dox = item.doc_value();
     if !dox.is_empty() {
-        let report_diag =
-            |cx: &DocContext<'_>, msg: &'static str, url: &str, range: Range<usize>| {
-                let sp =
-                    source_span_for_markdown_range(cx.tcx, &dox, &range, &item.attrs.doc_strings)
-                        .unwrap_or_else(|| item.attr_span(cx.tcx));
-                cx.tcx.node_span_lint(crate::lint::BARE_URLS, hir_id, sp, |lint| {
-                    lint.primary_message(msg)
-                        .note("bare URLs are not automatically turned into clickable links")
-                        .span_suggestion(
-                            sp,
-                            "use an automatic link instead",
-                            format!("<{url}>"),
-                            Applicability::MachineApplicable,
-                        );
-                });
-            };
+        let report_diag = |cx: &DocContext<'_>, msg: &'static str, range: Range<usize>| {
+            let sp = source_span_for_markdown_range(cx.tcx, &dox, &range, &item.attrs.doc_strings)
+                .unwrap_or_else(|| item.attr_span(cx.tcx));
+            cx.tcx.node_span_lint(crate::lint::BARE_URLS, hir_id, sp, |lint| {
+                lint.primary_message(msg)
+                    .note("bare URLs are not automatically turned into clickable links")
+                    .multipart_suggestion(
+                        "use an automatic link instead",
+                        vec![
+                            (sp.shrink_to_lo(), "<".to_string()),
+                            (sp.shrink_to_hi(), ">".to_string()),
+                        ],
+                        Applicability::MachineApplicable,
+                    );
+            });
+        };
 
         let mut p = Parser::new_ext(&dox, main_body_opts()).into_offset_iter();
 
@@ -74,17 +74,15 @@ fn find_raw_urls(
     cx: &DocContext<'_>,
     text: &str,
     range: Range<usize>,
-    f: &impl Fn(&DocContext<'_>, &'static str, &str, Range<usize>),
+    f: &impl Fn(&DocContext<'_>, &'static str, Range<usize>),
 ) {
     trace!("looking for raw urls in {text}");
     // For now, we only check "full" URLs (meaning, starting with "http://" or "https://").
     for match_ in URL_REGEX.find_iter(text) {
-        let url = match_.as_str();
         let url_range = match_.range();
         f(
             cx,
             "this URL is not a hyperlink",
-            url,
             Range { start: range.start + url_range.start, end: range.start + url_range.end },
         );
     }
diff --git a/src/rustdoc-json-types/lib.rs b/src/rustdoc-json-types/lib.rs
index 68030493e9c..89115d4d7d6 100644
--- a/src/rustdoc-json-types/lib.rs
+++ b/src/rustdoc-json-types/lib.rs
@@ -8,7 +8,7 @@ use serde::{Deserialize, Serialize};
 use std::path::PathBuf;
 
 /// rustdoc format-version.
-pub const FORMAT_VERSION: u32 = 30;
+pub const FORMAT_VERSION: u32 = 31;
 
 /// A `Crate` is the root of the emitted JSON blob. It contains all type/documentation information
 /// about the language items in the local crate, as well as info about external items to allow
@@ -511,9 +511,9 @@ pub enum WherePredicate {
         /// ```
         generic_params: Vec<GenericParamDef>,
     },
-    RegionPredicate {
+    LifetimePredicate {
         lifetime: String,
-        bounds: Vec<GenericBound>,
+        outlives: Vec<String>,
     },
     EqPredicate {
         lhs: Type,
diff --git a/src/tools/clippy/tests/ui/dbg_macro/dbg_macro.stderr b/src/tools/clippy/tests/ui/dbg_macro/dbg_macro.stderr
index 86667701da0..7d3c3f7c918 100644
--- a/src/tools/clippy/tests/ui/dbg_macro/dbg_macro.stderr
+++ b/src/tools/clippy/tests/ui/dbg_macro/dbg_macro.stderr
@@ -86,7 +86,6 @@ LL |     dbg!();
 help: remove the invocation before committing it to a version control system
    |
 LL -     dbg!();
-LL +     
    |
 
 error: the `dbg!` macro is intended as a debugging tool
@@ -146,7 +145,6 @@ LL |     expand_to_dbg!();
 help: remove the invocation before committing it to a version control system
    |
 LL -             dbg!();
-LL +             
    |
 
 error: the `dbg!` macro is intended as a debugging tool
diff --git a/src/tools/clippy/tests/ui/dbg_macro/dbg_macro_unfixable.stderr b/src/tools/clippy/tests/ui/dbg_macro/dbg_macro_unfixable.stderr
index d21595c2fcd..16e51f4742e 100644
--- a/src/tools/clippy/tests/ui/dbg_macro/dbg_macro_unfixable.stderr
+++ b/src/tools/clippy/tests/ui/dbg_macro/dbg_macro_unfixable.stderr
@@ -9,7 +9,6 @@ LL |     dbg!();
 help: remove the invocation before committing it to a version control system
    |
 LL -     dbg!();
-LL +     
    |
 
 error: the `dbg!` macro is intended as a debugging tool
diff --git a/src/tools/clippy/tests/ui/manual_split_once.stderr b/src/tools/clippy/tests/ui/manual_split_once.stderr
index b4e51f473cf..c5c9be3ac63 100644
--- a/src/tools/clippy/tests/ui/manual_split_once.stderr
+++ b/src/tools/clippy/tests/ui/manual_split_once.stderr
@@ -96,12 +96,10 @@ LL |     let (l, r) = "a.b.c".split_once('.').unwrap();
 help: remove the `iter` usages
    |
 LL -     let l = iter.next().unwrap();
-LL +     
    |
 help: remove the `iter` usages
    |
 LL -     let r = iter.next().unwrap();
-LL +     
    |
 
 error: manual implementation of `split_once`
@@ -121,12 +119,10 @@ LL |     let (l, r) = "a.b.c".split_once('.')?;
 help: remove the `iter` usages
    |
 LL -     let l = iter.next()?;
-LL +     
    |
 help: remove the `iter` usages
    |
 LL -     let r = iter.next()?;
-LL +     
    |
 
 error: manual implementation of `rsplit_once`
@@ -146,12 +142,10 @@ LL |     let (l, r) = "a.b.c".rsplit_once('.').unwrap();
 help: remove the `iter` usages
    |
 LL -     let r = iter.next().unwrap();
-LL +     
    |
 help: remove the `iter` usages
    |
 LL -     let l = iter.next().unwrap();
-LL +     
    |
 
 error: manual implementation of `rsplit_once`
@@ -171,12 +165,10 @@ LL |     let (l, r) = "a.b.c".rsplit_once('.')?;
 help: remove the `iter` usages
    |
 LL -     let r = iter.next()?;
-LL +     
    |
 help: remove the `iter` usages
    |
 LL -     let l = iter.next()?;
-LL +     
    |
 
 error: manual implementation of `split_once`
@@ -202,12 +194,10 @@ LL |     let (a, b) = "a.b.c".split_once('.').unwrap();
 help: remove the `iter` usages
    |
 LL -     let a = iter.next().unwrap();
-LL +     
    |
 help: remove the `iter` usages
    |
 LL -     let b = iter.next().unwrap();
-LL +     
    |
 
 error: aborting due to 19 previous errors
diff --git a/src/tools/clippy/tests/ui/significant_drop_tightening.stderr b/src/tools/clippy/tests/ui/significant_drop_tightening.stderr
index f818a14cbe6..5fc66279f00 100644
--- a/src/tools/clippy/tests/ui/significant_drop_tightening.stderr
+++ b/src/tools/clippy/tests/ui/significant_drop_tightening.stderr
@@ -64,7 +64,6 @@ LL +         let rslt0 = mutex.lock().unwrap().abs();
 help: remove separated single usage
    |
 LL -         let rslt0 = lock.abs();
-LL +         
    |
 
 error: temporary with significant `Drop` can be early dropped
@@ -88,7 +87,6 @@ LL +         mutex.lock().unwrap().clear();
 help: remove separated single usage
    |
 LL -         lock.clear();
-LL +         
    |
 
 error: aborting due to 4 previous errors
diff --git a/src/tools/jsondocck/src/cache.rs b/src/tools/jsondocck/src/cache.rs
index 50697d46b8c..5f72bd171a1 100644
--- a/src/tools/jsondocck/src/cache.rs
+++ b/src/tools/jsondocck/src/cache.rs
@@ -23,7 +23,7 @@ impl Cache {
 
         Cache {
             value: serde_json::from_str::<Value>(&content).expect("failed to convert from JSON"),
-            variables: HashMap::new(),
+            variables: HashMap::from([("FILE".to_owned(), config.template.clone().into())]),
         }
     }
 
diff --git a/src/tools/jsondocck/src/main.rs b/src/tools/jsondocck/src/main.rs
index 688b403bf0e..429c6151796 100644
--- a/src/tools/jsondocck/src/main.rs
+++ b/src/tools/jsondocck/src/main.rs
@@ -56,6 +56,8 @@ pub enum CommandKind {
 
 impl CommandKind {
     fn validate(&self, args: &[String], lineno: usize) -> bool {
+        // FIXME(adotinthevoid): We should "parse, don't validate" here, so we avoid ad-hoc
+        // indexing in check_command.
         let count = match self {
             CommandKind::Has => (1..=2).contains(&args.len()),
             CommandKind::IsMany => args.len() >= 2,
@@ -71,7 +73,7 @@ impl CommandKind {
         if let CommandKind::Count = self {
             if args[1].parse::<usize>().is_err() {
                 print_err(
-                    &format!("Second argument to @count must be a valid usize (got `{}`)", args[2]),
+                    &format!("Second argument to @count must be a valid usize (got `{}`)", args[1]),
                     lineno,
                 );
                 return false;
diff --git a/src/tools/jsondoclint/src/validator.rs b/src/tools/jsondoclint/src/validator.rs
index 1713a4d812c..cd011dce784 100644
--- a/src/tools/jsondoclint/src/validator.rs
+++ b/src/tools/jsondoclint/src/validator.rs
@@ -374,8 +374,8 @@ impl<'a> Validator<'a> {
                 bounds.iter().for_each(|b| self.check_generic_bound(b));
                 generic_params.iter().for_each(|gpd| self.check_generic_param_def(gpd));
             }
-            WherePredicate::RegionPredicate { lifetime: _, bounds } => {
-                bounds.iter().for_each(|b| self.check_generic_bound(b));
+            WherePredicate::LifetimePredicate { lifetime: _, outlives: _ } => {
+                // nop, all strings.
             }
             WherePredicate::EqPredicate { lhs, rhs } => {
                 self.check_type(lhs);
diff --git a/src/tools/miri/rust-version b/src/tools/miri/rust-version
index 5a35166769e..dd5355134c5 100644
--- a/src/tools/miri/rust-version
+++ b/src/tools/miri/rust-version
@@ -1 +1 @@
-66b4f0021bfb11a8c20d084c99a40f4a78ce1d38
+51917ba8f215f76e9d3fa8e77cd0a781bb28dab7
diff --git a/src/tools/miri/src/shims/backtrace.rs b/src/tools/miri/src/shims/backtrace.rs
index 06be9c1e63e..24a4b5f26a9 100644
--- a/src/tools/miri/src/shims/backtrace.rs
+++ b/src/tools/miri/src/shims/backtrace.rs
@@ -119,7 +119,7 @@ pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
         let (alloc_id, offset, _prov) = this.ptr_get_alloc_id(ptr)?;
 
         // This has to be an actual global fn ptr, not a dlsym function.
-        let fn_instance = if let Some(GlobalAlloc::Function(instance)) =
+        let fn_instance = if let Some(GlobalAlloc::Function { instance, .. }) =
             this.tcx.try_get_global_alloc(alloc_id)
         {
             instance
diff --git a/src/tools/miri/tests/pass/function_pointers.rs b/src/tools/miri/tests/pass/function_pointers.rs
index 36679b7180a..2aa3ebf2dd0 100644
--- a/src/tools/miri/tests/pass/function_pointers.rs
+++ b/src/tools/miri/tests/pass/function_pointers.rs
@@ -23,6 +23,7 @@ fn h(i: i32, j: i32) -> i32 {
     j * i * 7
 }
 
+#[inline(never)]
 fn i() -> i32 {
     73
 }
@@ -77,7 +78,7 @@ fn main() {
     assert_eq!(indirect_mut3(h), 210);
     assert_eq!(indirect_once3(h), 210);
     // Check that `i` always has the same address. This is not guaranteed
-    // but Miri currently uses a fixed address for monomorphic functions.
+    // but Miri currently uses a fixed address for non-inlineable monomorphic functions.
     assert!(return_fn_ptr(i) == i);
     assert!(return_fn_ptr(i) as unsafe fn() -> i32 == i as fn() -> i32 as unsafe fn() -> i32);
     // Miri gives different addresses to different reifications of a generic function.
diff --git a/src/tools/miri/tests/pass/issues/issue-91636.rs b/src/tools/miri/tests/pass/issues/issue-91636.rs
index 21000bb68d2..00370165812 100644
--- a/src/tools/miri/tests/pass/issues/issue-91636.rs
+++ b/src/tools/miri/tests/pass/issues/issue-91636.rs
@@ -10,6 +10,7 @@ impl Function {
     }
 }
 
+#[inline(never)]
 fn dummy(_: &str) {}
 
 fn main() {
diff --git a/src/tools/run-make-support/src/rustc.rs b/src/tools/run-make-support/src/rustc.rs
index 054836e87cf..885b361f72a 100644
--- a/src/tools/run-make-support/src/rustc.rs
+++ b/src/tools/run-make-support/src/rustc.rs
@@ -108,7 +108,11 @@ impl Rustc {
     }
 
     /// Remap source path prefixes in all output.
-    pub fn remap_path_prefix<P: AsRef<Path>>(&mut self, from: P, to: P) -> &mut Self {
+    pub fn remap_path_prefix<P: AsRef<Path>, P2: AsRef<Path>>(
+        &mut self,
+        from: P,
+        to: P2,
+    ) -> &mut Self {
         let from = from.as_ref().to_string_lossy();
         let to = to.as_ref().to_string_lossy();
 
diff --git a/src/tools/tidy/src/run_make_tests.rs b/src/tools/tidy/src/run_make_tests.rs
index 2d9f8448a35..8d176787837 100644
--- a/src/tools/tidy/src/run_make_tests.rs
+++ b/src/tools/tidy/src/run_make_tests.rs
@@ -95,7 +95,7 @@ pub fn check(tests_path: &Path, src_path: &Path, bless: bool, bad: &mut bool) {
             tidy_error!(
                 bad,
                 "Makefile `{}` no longer exists and should be removed from the exclusions in \
-                `src/tools/tidy/src/allowed_run_make_makefiles.txt`, you can run --bless to update \
+                `src/tools/tidy/src/allowed_run_make_makefiles.txt`, you can run `x test tidy --bless` to update \
                 the allow list",
                 p.display()
             );