From d6b88a5bb700311d0e8cfa2c3d63a2b12233ae33 Mon Sep 17 00:00:00 2001
From: Vladimir Makayev <vmakaev@fb.com>
Date: Sun, 28 Apr 2024 15:26:38 -0700
Subject: [PATCH 01/16] add support to override lldb binary path for ./x test

---
 src/bootstrap/src/core/build_steps/test.rs | 7 ++++---
 src/bootstrap/src/core/config/config.rs    | 4 ++++
 src/bootstrap/src/utils/change_tracker.rs  | 5 +++++
 3 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs
index d581987c29e5d..3ac829c36556c 100644
--- a/src/bootstrap/src/core/build_steps/test.rs
+++ b/src/bootstrap/src/core/build_steps/test.rs
@@ -1927,15 +1927,16 @@ NOTE: if you're sure you want to do this, please open an issue as to why. In the
                     .to_string()
             })
         };
-        let lldb_exe = "lldb";
-        let lldb_version = Command::new(lldb_exe)
+
+        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())
             .ok();
         if let Some(ref vers) = lldb_version {
             cmd.arg("--lldb-version").arg(vers);
-            let lldb_python_dir = run(Command::new(lldb_exe).arg("-P")).ok();
+            let lldb_python_dir = run(Command::new(&lldb_exe).arg("-P")).ok();
             if let Some(ref dir) = lldb_python_dir {
                 cmd.arg("--lldb-python-dir").arg(dir);
             }
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 2acce6273598c..ef5ba2cc34038 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -329,6 +329,7 @@ pub struct Config {
     pub nodejs: Option<PathBuf>,
     pub npm: Option<PathBuf>,
     pub gdb: Option<PathBuf>,
+    pub lldb: Option<PathBuf>,
     pub python: Option<PathBuf>,
     pub reuse: Option<PathBuf>,
     pub cargo_native_static: bool,
@@ -832,6 +833,7 @@ define_config! {
         docs_minification: Option<bool> = "docs-minification",
         submodules: Option<bool> = "submodules",
         gdb: Option<String> = "gdb",
+        lldb: Option<String> = "lldb",
         nodejs: Option<String> = "nodejs",
         npm: Option<String> = "npm",
         python: Option<String> = "python",
@@ -1408,6 +1410,7 @@ impl Config {
             docs_minification,
             submodules,
             gdb,
+            lldb,
             nodejs,
             npm,
             python,
@@ -1500,6 +1503,7 @@ impl Config {
         config.nodejs = nodejs.map(PathBuf::from);
         config.npm = npm.map(PathBuf::from);
         config.gdb = gdb.map(PathBuf::from);
+        config.lldb = lldb.map(PathBuf::from);
         config.python = python.map(PathBuf::from);
         config.reuse = reuse.map(PathBuf::from);
         config.submodules = submodules;
diff --git a/src/bootstrap/src/utils/change_tracker.rs b/src/bootstrap/src/utils/change_tracker.rs
index db3df598a0c63..c3a03693f714f 100644
--- a/src/bootstrap/src/utils/change_tracker.rs
+++ b/src/bootstrap/src/utils/change_tracker.rs
@@ -175,4 +175,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Warning,
         summary: "The deprecated field `changelog-seen` has been removed. Using that field in `config.toml` from now on will result in breakage.",
     },
+    ChangeInfo {
+        change_id: 124501,
+        severity: ChangeSeverity::Info,
+        summary: "New option `build.lldb` that will override the default lldb binary path used in debuginfo tests",
+    },
 ];

From fca7c0402ac5107943be79be8532639afc149af4 Mon Sep 17 00:00:00 2001
From: onur-ozkan <work@onurozkan.dev>
Date: Wed, 1 May 2024 06:35:39 +0300
Subject: [PATCH 02/16] add a reference link to the comment of the "cc" and
 "cmake".

Signed-off-by: onur-ozkan <work@onurozkan.dev>
---
 src/bootstrap/Cargo.toml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/bootstrap/Cargo.toml b/src/bootstrap/Cargo.toml
index c7a513d08908a..e9675e204523f 100644
--- a/src/bootstrap/Cargo.toml
+++ b/src/bootstrap/Cargo.toml
@@ -33,9 +33,9 @@ path = "src/bin/sccache-plus-cl.rs"
 test = false
 
 [dependencies]
-# Most of the time updating these dependencies requires modifications
-# to the bootstrap codebase; otherwise, some targets will fail. That's
-# why these dependencies are explicitly pinned.
+# Most of the time updating these dependencies requires modifications to the
+# bootstrap codebase(e.g., https://github.com/rust-lang/rust/issues/124565);
+# otherwise, some targets will fail. That's why these dependencies are explicitly pinned.
 cc = "=1.0.73"
 cmake = "=0.1.48"
 

From 27d1d0a6a41059a6e499b137ef8b3cc50fb610b6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <berykubik@gmail.com>
Date: Fri, 3 May 2024 15:49:15 +0200
Subject: [PATCH 03/16] Do not include Docker version in caching key

We are now using Docker caching directly rather than downloading archives from S3, so it should not be needed.

This should unblock reusing the cache locally.
---
 src/ci/docker/run.sh | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/ci/docker/run.sh b/src/ci/docker/run.sh
index fcc507b572c27..b9a559039e09f 100755
--- a/src/ci/docker/run.sh
+++ b/src/ci/docker/run.sh
@@ -71,8 +71,6 @@ if [ -f "$docker_dir/$image/Dockerfile" ]; then
       # only run in x86_64 machines.
       uname -m >> $hash_key
 
-      docker --version >> $hash_key
-
       # Include cache version. Can be used to manually bust the Docker cache.
       echo "2" >> $hash_key
 

From 0372065097ec04e65fcf105c2a07f4cda5ed29f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <berykubik@gmail.com>
Date: Fri, 3 May 2024 15:50:02 +0200
Subject: [PATCH 04/16] Calculate the Docker hash key also locally

---
 src/ci/docker/run.sh | 60 +++++++++++++++++++++-----------------------
 1 file changed, 29 insertions(+), 31 deletions(-)

diff --git a/src/ci/docker/run.sh b/src/ci/docker/run.sh
index b9a559039e09f..acd88870b169f 100755
--- a/src/ci/docker/run.sh
+++ b/src/ci/docker/run.sh
@@ -50,37 +50,35 @@ fi
 CACHE_DOMAIN="${CACHE_DOMAIN:-ci-caches.rust-lang.org}"
 
 if [ -f "$docker_dir/$image/Dockerfile" ]; then
-    if isCI; then
-      hash_key=/tmp/.docker-hash-key.txt
-      rm -f "${hash_key}"
-      echo $image >> $hash_key
-
-      cat "$docker_dir/$image/Dockerfile" >> $hash_key
-      # Look for all source files involves in the COPY command
-      copied_files=/tmp/.docker-copied-files.txt
-      rm -f "$copied_files"
-      for i in $(sed -n -e '/^COPY --from=/! s/^COPY \(.*\) .*$/\1/p' \
-          "$docker_dir/$image/Dockerfile"); do
-        # List the file names
-        find "$script_dir/$i" -type f >> $copied_files
-      done
-      # Sort the file names and cat the content into the hash key
-      sort $copied_files | xargs cat >> $hash_key
-
-      # Include the architecture in the hash key, since our Linux CI does not
-      # only run in x86_64 machines.
-      uname -m >> $hash_key
-
-      # Include cache version. Can be used to manually bust the Docker cache.
-      echo "2" >> $hash_key
-
-      echo "Image input"
-      cat $hash_key
-
-      cksum=$(sha512sum $hash_key | \
-        awk '{print $1}')
-      echo "Image input checksum ${cksum}"
-    fi
+    hash_key=/tmp/.docker-hash-key.txt
+    rm -f "${hash_key}"
+    echo $image >> $hash_key
+
+    cat "$docker_dir/$image/Dockerfile" >> $hash_key
+    # Look for all source files involves in the COPY command
+    copied_files=/tmp/.docker-copied-files.txt
+    rm -f "$copied_files"
+    for i in $(sed -n -e '/^COPY --from=/! s/^COPY \(.*\) .*$/\1/p' \
+      "$docker_dir/$image/Dockerfile"); do
+    # List the file names
+    find "$script_dir/$i" -type f >> $copied_files
+    done
+    # Sort the file names and cat the content into the hash key
+    sort $copied_files | xargs cat >> $hash_key
+
+    # Include the architecture in the hash key, since our Linux CI does not
+    # only run in x86_64 machines.
+    uname -m >> $hash_key
+
+    # Include cache version. Can be used to manually bust the Docker cache.
+    echo "2" >> $hash_key
+
+    echo "Image input"
+    cat $hash_key
+
+    cksum=$(sha512sum $hash_key | \
+    awk '{print $1}')
+    echo "Image input checksum ${cksum}"
 
     dockerfile="$docker_dir/$image/Dockerfile"
     if [ -x /usr/bin/cygpath ]; then

From 02f4ef7cde5ab7b69545791f3750ae03d251e8ae Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jakub=20Ber=C3=A1nek?= <berykubik@gmail.com>
Date: Fri, 3 May 2024 15:52:00 +0200
Subject: [PATCH 05/16] Allow reusing CI Docker cache when running CI images
 locally

---
 src/ci/docker/run.sh | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/src/ci/docker/run.sh b/src/ci/docker/run.sh
index acd88870b169f..22dcb808c743e 100755
--- a/src/ci/docker/run.sh
+++ b/src/ci/docker/run.sh
@@ -101,10 +101,18 @@ if [ -f "$docker_dir/$image/Dockerfile" ]; then
     # It seems that it cannot be the same as $IMAGE_TAG, otherwise it overwrites the cache
     CACHE_IMAGE_TAG=${REGISTRY}/${REGISTRY_USERNAME}/rust-ci-cache:${cksum}
 
-    # On non-CI jobs, we don't do any caching.
+    # On non-CI jobs, we try to download a pre-built image from the rust-lang-ci
+    # ghcr.io registry. If it is not possible, we fall back to building the image
+    # locally.
     if ! isCI;
     then
-        retry docker build --rm -t rust-ci -f "$dockerfile" "$context"
+        if docker pull "${IMAGE_TAG}"; then
+            echo "Downloaded Docker image from CI"
+            docker tag "${IMAGE_TAG}" rust-ci
+        else
+            echo "Building local Docker image"
+            retry docker build --rm -t rust-ci -f "$dockerfile" "$context"
+        fi
     # On PR CI jobs, we don't have permissions to write to the registry cache,
     # but we can still read from it.
     elif [[ "$PR_CI_JOB" == "1" ]];

From dcf68536930cc60699339212bbb54b5f4af4e09e Mon Sep 17 00:00:00 2001
From: Urgau <urgau@numericable.fr>
Date: Sat, 4 May 2024 17:26:15 +0200
Subject: [PATCH 06/16] Update Cargo diagnostics in check-cfg

---
 .../src/context/diagnostics/check_cfg.rs       |  8 ++++----
 tests/ui/check-cfg/cargo-feature.none.stderr   | 12 ++++++------
 tests/ui/check-cfg/cargo-feature.some.stderr   | 12 ++++++------
 tests/ui/check-cfg/diagnotics.cargo.stderr     | 18 +++++++++---------
 4 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs b/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs
index e9a6276192e52..3c423b4e2aa6d 100644
--- a/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs
+++ b/compiler/rustc_lint/src/context/diagnostics/check_cfg.rs
@@ -164,9 +164,9 @@ pub(super) fn unexpected_cfg_name(
 
     if is_from_cargo {
         if !is_feature_cfg {
-            diag.help(format!("consider using a Cargo feature instead or adding `println!(\"cargo:rustc-check-cfg={inst}\");` to the top of a `build.rs`"));
+            diag.help(format!("consider using a Cargo feature instead or adding `println!(\"cargo::rustc-check-cfg={inst}\");` to the top of the `build.rs`"));
         }
-        diag.note("see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration");
+        diag.note("see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration");
     } else {
         diag.help(format!("to expect this configuration use `--check-cfg={inst}`"));
         diag.note("see <https://doc.rust-lang.org/nightly/rustc/check-cfg.html> for more information about checking conditional configuration");
@@ -266,9 +266,9 @@ pub(super) fn unexpected_cfg_value(
                 diag.help("consider defining some features in `Cargo.toml`");
             }
         } else if !is_cfg_a_well_know_name {
-            diag.help(format!("consider using a Cargo feature instead or adding `println!(\"cargo:rustc-check-cfg={inst}\");` to the top of a `build.rs`"));
+            diag.help(format!("consider using a Cargo feature instead or adding `println!(\"cargo::rustc-check-cfg={inst}\");` to the top of the `build.rs`"));
         }
-        diag.note("see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration");
+        diag.note("see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration");
     } else {
         if !is_cfg_a_well_know_name {
             diag.help(format!("to expect this configuration use `--check-cfg={inst}`"));
diff --git a/tests/ui/check-cfg/cargo-feature.none.stderr b/tests/ui/check-cfg/cargo-feature.none.stderr
index 09a1c95026722..ae2351b82ce81 100644
--- a/tests/ui/check-cfg/cargo-feature.none.stderr
+++ b/tests/ui/check-cfg/cargo-feature.none.stderr
@@ -6,7 +6,7 @@ LL | #[cfg(feature = "serde")]
    |
    = note: no expected values for `feature`
    = help: consider adding `serde` as a feature in `Cargo.toml`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value: (none)
@@ -17,7 +17,7 @@ LL | #[cfg(feature)]
    |
    = note: no expected values for `feature`
    = help: consider defining some features in `Cargo.toml`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition name: `tokio_unstable`
   --> $DIR/cargo-feature.rs:22:7
@@ -26,8 +26,8 @@ LL | #[cfg(tokio_unstable)]
    |       ^^^^^^^^^^^^^^
    |
    = help: expected names are: `clippy`, `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, `windows`
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(tokio_unstable)");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(tokio_unstable)");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition name: `CONFIG_NVME`
   --> $DIR/cargo-feature.rs:26:7
@@ -35,8 +35,8 @@ warning: unexpected `cfg` condition name: `CONFIG_NVME`
 LL | #[cfg(CONFIG_NVME = "m")]
    |       ^^^^^^^^^^^^^^^^^
    |
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(CONFIG_NVME, values(\"m\"))");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(CONFIG_NVME, values(\"m\"))");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: 4 warnings emitted
 
diff --git a/tests/ui/check-cfg/cargo-feature.some.stderr b/tests/ui/check-cfg/cargo-feature.some.stderr
index 4db9c66fc8692..191efbf2d54d2 100644
--- a/tests/ui/check-cfg/cargo-feature.some.stderr
+++ b/tests/ui/check-cfg/cargo-feature.some.stderr
@@ -6,7 +6,7 @@ LL | #[cfg(feature = "serde")]
    |
    = note: expected values for `feature` are: `bitcode`
    = help: consider adding `serde` as a feature in `Cargo.toml`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition value: (none)
@@ -17,7 +17,7 @@ LL | #[cfg(feature)]
    |
    = note: expected values for `feature` are: `bitcode`
    = help: consider defining some features in `Cargo.toml`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition name: `tokio_unstable`
   --> $DIR/cargo-feature.rs:22:7
@@ -26,8 +26,8 @@ LL | #[cfg(tokio_unstable)]
    |       ^^^^^^^^^^^^^^
    |
    = help: expected names are: `CONFIG_NVME`, `clippy`, `debug_assertions`, `doc`, `doctest`, `feature`, `miri`, `overflow_checks`, `panic`, `proc_macro`, `relocation_model`, `sanitize`, `sanitizer_cfi_generalize_pointers`, `sanitizer_cfi_normalize_integers`, `target_abi`, `target_arch`, `target_endian`, `target_env`, `target_family`, `target_feature`, `target_has_atomic`, `target_has_atomic_equal_alignment`, `target_has_atomic_load_store`, `target_os`, `target_pointer_width`, `target_thread_local`, `target_vendor`, `test`, `ub_checks`, `unix`, `windows`
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(tokio_unstable)");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(tokio_unstable)");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition value: `m`
   --> $DIR/cargo-feature.rs:26:7
@@ -38,8 +38,8 @@ LL | #[cfg(CONFIG_NVME = "m")]
    |                     help: there is a expected value with a similar name: `"y"`
    |
    = note: expected values for `CONFIG_NVME` are: `y`
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(CONFIG_NVME, values(\"m\"))");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(CONFIG_NVME, values(\"m\"))");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: 4 warnings emitted
 
diff --git a/tests/ui/check-cfg/diagnotics.cargo.stderr b/tests/ui/check-cfg/diagnotics.cargo.stderr
index 16417fe010544..1b7505682da36 100644
--- a/tests/ui/check-cfg/diagnotics.cargo.stderr
+++ b/tests/ui/check-cfg/diagnotics.cargo.stderr
@@ -5,7 +5,7 @@ LL | #[cfg(featur)]
    |       ^^^^^^ help: there is a config with a similar name: `feature`
    |
    = help: expected values for `feature` are: `foo`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
    = note: `#[warn(unexpected_cfgs)]` on by default
 
 warning: unexpected `cfg` condition name: `featur`
@@ -14,7 +14,7 @@ warning: unexpected `cfg` condition name: `featur`
 LL | #[cfg(featur = "foo")]
    |       ^^^^^^^^^^^^^^
    |
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 help: there is a config with a similar name and value
    |
 LL | #[cfg(feature = "foo")]
@@ -27,7 +27,7 @@ LL | #[cfg(featur = "fo")]
    |       ^^^^^^^^^^^^^
    |
    = help: expected values for `feature` are: `foo`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 help: there is a config with a similar name and different values
    |
 LL | #[cfg(feature = "foo")]
@@ -39,8 +39,8 @@ warning: unexpected `cfg` condition name: `no_value`
 LL | #[cfg(no_value)]
    |       ^^^^^^^^ help: there is a config with a similar name: `no_values`
    |
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(no_value)");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(no_value)");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: unexpected `cfg` condition name: `no_value`
   --> $DIR/diagnotics.rs:27:7
@@ -48,8 +48,8 @@ warning: unexpected `cfg` condition name: `no_value`
 LL | #[cfg(no_value = "foo")]
    |       ^^^^^^^^^^^^^^^^
    |
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(no_value, values(\"foo\"))");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(no_value, values(\"foo\"))");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 help: there is a config with a similar name and no value
    |
 LL | #[cfg(no_values)]
@@ -64,8 +64,8 @@ LL | #[cfg(no_values = "bar")]
    |                help: remove the value
    |
    = note: no expected value for `no_values`
-   = help: consider using a Cargo feature instead or adding `println!("cargo:rustc-check-cfg=cfg(no_values, values(\"bar\"))");` to the top of a `build.rs`
-   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#check-cfg> for more information about checking conditional configuration
+   = help: consider using a Cargo feature instead or adding `println!("cargo::rustc-check-cfg=cfg(no_values, values(\"bar\"))");` to the top of the `build.rs`
+   = note: see <https://doc.rust-lang.org/nightly/cargo/reference/build-scripts.html#rustc-check-cfg> for more information about checking conditional configuration
 
 warning: 6 warnings emitted
 

From 6714216eaa8e3431706e451e2ff26401551207ea Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Fri, 3 May 2024 20:08:35 -0400
Subject: [PATCH 07/16] Only consider ambiguous goals when finding best
 obligation for ambiguities

---
 .../src/solve/fulfill.rs                      | 20 +++++++++--------
 .../incompleteness-unstable-result.rs         |  2 +-
 .../incompleteness-unstable-result.stderr     | 22 ++++++++++---------
 3 files changed, 24 insertions(+), 20 deletions(-)

diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs
index 796222129f180..c0ece9655a5af 100644
--- a/compiler/rustc_trait_selection/src/solve/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs
@@ -137,7 +137,7 @@ impl<'tcx> TraitEngine<'tcx> for FulfillmentCtxt<'tcx> {
             .collect();
 
         errors.extend(self.obligations.overflowed.drain(..).map(|obligation| FulfillmentError {
-            obligation: find_best_leaf_obligation(infcx, &obligation),
+            obligation: find_best_leaf_obligation(infcx, &obligation, true),
             code: FulfillmentErrorCode::Ambiguity { overflow: Some(true) },
             root_obligation: obligation,
         }));
@@ -198,7 +198,7 @@ fn fulfillment_error_for_no_solution<'tcx>(
     infcx: &InferCtxt<'tcx>,
     root_obligation: PredicateObligation<'tcx>,
 ) -> FulfillmentError<'tcx> {
-    let obligation = find_best_leaf_obligation(infcx, &root_obligation);
+    let obligation = find_best_leaf_obligation(infcx, &root_obligation, false);
 
     let code = match obligation.predicate.kind().skip_binder() {
         ty::PredicateKind::Clause(ty::ClauseKind::Projection(_)) => {
@@ -266,7 +266,7 @@ fn fulfillment_error_for_stalled<'tcx>(
     });
 
     FulfillmentError {
-        obligation: find_best_leaf_obligation(infcx, &obligation),
+        obligation: find_best_leaf_obligation(infcx, &obligation, true),
         code,
         root_obligation: obligation,
     }
@@ -275,12 +275,13 @@ fn fulfillment_error_for_stalled<'tcx>(
 fn find_best_leaf_obligation<'tcx>(
     infcx: &InferCtxt<'tcx>,
     obligation: &PredicateObligation<'tcx>,
+    consider_ambiguities: bool,
 ) -> PredicateObligation<'tcx> {
     let obligation = infcx.resolve_vars_if_possible(obligation.clone());
     infcx
         .visit_proof_tree(
             obligation.clone().into(),
-            &mut BestObligation { obligation: obligation.clone() },
+            &mut BestObligation { obligation: obligation.clone(), consider_ambiguities },
         )
         .break_value()
         .unwrap_or(obligation)
@@ -288,6 +289,7 @@ fn find_best_leaf_obligation<'tcx>(
 
 struct BestObligation<'tcx> {
     obligation: PredicateObligation<'tcx>,
+    consider_ambiguities: bool,
 }
 
 impl<'tcx> BestObligation<'tcx> {
@@ -355,11 +357,11 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
                 }
             }
 
-            // Skip nested goals that hold.
-            //FIXME: We should change the max allowed certainty based on if we're
-            // visiting an ambiguity or error obligation.
-            if matches!(nested_goal.result(), Ok(Certainty::Yes)) {
-                continue;
+            // Skip nested goals that aren't the *reason* for our goal's failure.
+            match self.consider_ambiguities {
+                true if matches!(nested_goal.result(), Ok(Certainty::Maybe(_))) => {}
+                false if matches!(nested_goal.result(), Err(_)) => {}
+                _ => continue,
             }
 
             self.with_derived_obligation(obligation, |this| nested_goal.visit_with(this))?;
diff --git a/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.rs b/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.rs
index bc9bb6ce2d79e..8bb4ff469076c 100644
--- a/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.rs
+++ b/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.rs
@@ -61,7 +61,7 @@ where
     // entering the cycle from `A` fails, but would work if we were to use the cache
     // result of `B<X>`.
     impls_trait::<A<X>, _, _, _>();
-    //~^ ERROR the trait bound `X: IncompleteGuidance<_, _>` is not satisfied
+    //~^ ERROR the trait bound `A<X>: Trait<i32, u8, u8>` is not satisfied
 }
 
 fn main() {
diff --git a/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.stderr b/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.stderr
index 78116ebba8274..cdb4ff4588f75 100644
--- a/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.stderr
+++ b/tests/ui/traits/next-solver/cycles/coinduction/incompleteness-unstable-result.stderr
@@ -1,26 +1,28 @@
-error[E0277]: the trait bound `X: IncompleteGuidance<_, _>` is not satisfied
+error[E0277]: the trait bound `A<X>: Trait<i32, u8, u8>` is not satisfied
   --> $DIR/incompleteness-unstable-result.rs:63:19
    |
 LL |     impls_trait::<A<X>, _, _, _>();
-   |                   ^^^^ the trait `IncompleteGuidance<_, _>` is not implemented for `X`, which is required by `A<X>: Trait<_, _, _>`
+   |                   ^^^^ the trait `Trait<i32, u8, u8>` is not implemented for `A<X>`, which is required by `A<X>: Trait<_, _, _>`
    |
-   = help: the following other types implement trait `IncompleteGuidance<T, V>`:
-             <T as IncompleteGuidance<U, i16>>
-             <T as IncompleteGuidance<U, i8>>
-             <T as IncompleteGuidance<U, u8>>
-note: required for `A<X>` to implement `Trait<_, _, u8>`
+note: required for `A<X>` to implement `Trait<i32, u8, u8>`
   --> $DIR/incompleteness-unstable-result.rs:32:50
    |
 LL | impl<T: ?Sized, U: ?Sized, V: ?Sized, D: ?Sized> Trait<U, V, D> for A<T>
    |                                                  ^^^^^^^^^^^^^^     ^^^^
-LL | where
-LL |     T: IncompleteGuidance<U, V>,
-   |        ------------------------ unsatisfied trait bound introduced here
+...
+LL |     A<T>: Trait<U, D, V>,
+   |           -------------- unsatisfied trait bound introduced here
+   = note: 8 redundant requirements hidden
+   = note: required for `A<X>` to implement `Trait<i32, u8, u8>`
 note: required by a bound in `impls_trait`
   --> $DIR/incompleteness-unstable-result.rs:51:28
    |
 LL | fn impls_trait<T: ?Sized + Trait<U, V, D>, U: ?Sized, V: ?Sized, D: ?Sized>() {}
    |                            ^^^^^^^^^^^^^^ required by this bound in `impls_trait`
+help: consider extending the `where` clause, but there might be an alternative better way to express this requirement
+   |
+LL |     X: IncompleteGuidance<u32, i16>, A<X>: Trait<i32, u8, u8>
+   |                                    ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 error: aborting due to 1 previous error
 

From b33599485b531b265e8167b547b25aba8ab05228 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Sat, 4 May 2024 12:37:14 -0400
Subject: [PATCH 08/16] Implement do_not_recommend in the new solver

---
 compiler/rustc_feature/src/builtin_attrs.rs   |  2 +-
 .../src/solve/fulfill.rs                      |  9 ++++++++
 .../do_not_recommend/simple.current.stderr    | 20 ++++++++++++++++
 .../do_not_recommend/simple.next.stderr       | 15 ++++++++++++
 .../do_not_recommend/simple.rs                | 23 +++++++++++++++++++
 5 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr
 create mode 100644 tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr
 create mode 100644 tests/ui/diagnostic_namespace/do_not_recommend/simple.rs

diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs
index 9c33cc8ed0b9c..dbb88e42a3eb9 100644
--- a/compiler/rustc_feature/src/builtin_attrs.rs
+++ b/compiler/rustc_feature/src/builtin_attrs.rs
@@ -518,7 +518,7 @@ pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[
     // RFC 2397
     gated!(
         do_not_recommend, Normal, template!(Word), WarnFollowing,
-        EncodeCrossCrate::No, experimental!(do_not_recommend)
+        EncodeCrossCrate::Yes, experimental!(do_not_recommend)
     ),
 
     // `#[cfi_encoding = ""]`
diff --git a/compiler/rustc_trait_selection/src/solve/fulfill.rs b/compiler/rustc_trait_selection/src/solve/fulfill.rs
index 796222129f180..c72488331e828 100644
--- a/compiler/rustc_trait_selection/src/solve/fulfill.rs
+++ b/compiler/rustc_trait_selection/src/solve/fulfill.rs
@@ -11,6 +11,7 @@ use rustc_infer::traits::{
 };
 use rustc_middle::ty::error::{ExpectedFound, TypeError};
 use rustc_middle::ty::{self, TyCtxt};
+use rustc_span::symbol::sym;
 
 use super::eval_ctxt::GenerateProofTree;
 use super::inspect::{ProofTreeInferCtxtExt, ProofTreeVisitor};
@@ -320,6 +321,14 @@ impl<'tcx> ProofTreeVisitor<'tcx> for BestObligation<'tcx> {
             return ControlFlow::Break(self.obligation.clone());
         };
 
+        // Don't walk into impls that have `do_not_recommend`.
+        if let ProbeKind::TraitCandidate { source: CandidateSource::Impl(impl_def_id), result: _ } =
+            candidate.kind()
+            && goal.infcx().tcx.has_attr(impl_def_id, sym::do_not_recommend)
+        {
+            return ControlFlow::Break(self.obligation.clone());
+        }
+
         // FIXME: Could we extract a trait ref from a projection here too?
         // FIXME: Also, what about considering >1 layer up the stack? May be necessary
         // for normalizes-to.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr
new file mode 100644
index 0000000000000..a4d4b7b359ec8
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/simple.current.stderr
@@ -0,0 +1,20 @@
+error[E0277]: the trait bound `*mut (): Foo` is not satisfied
+  --> $DIR/simple.rs:19:17
+   |
+LL |     needs_foo::<*mut ()>();
+   |                 ^^^^^^^ the trait `Send` is not implemented for `*mut ()`, which is required by `*mut (): Foo`
+   |
+note: required for `*mut ()` to implement `Foo`
+  --> $DIR/simple.rs:10:9
+   |
+LL | impl<T> Foo for T where T: Send {}
+   |         ^^^     ^          ---- unsatisfied trait bound introduced here
+note: required by a bound in `needs_foo`
+  --> $DIR/simple.rs:14:17
+   |
+LL | fn needs_foo<T: Foo>() {}
+   |                 ^^^ required by this bound in `needs_foo`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr b/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr
new file mode 100644
index 0000000000000..1341ca8175aff
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/simple.next.stderr
@@ -0,0 +1,15 @@
+error[E0277]: the trait bound `*mut (): Foo` is not satisfied
+  --> $DIR/simple.rs:19:17
+   |
+LL |     needs_foo::<*mut ()>();
+   |                 ^^^^^^^ the trait `Foo` is not implemented for `*mut ()`
+   |
+note: required by a bound in `needs_foo`
+  --> $DIR/simple.rs:14:17
+   |
+LL | fn needs_foo<T: Foo>() {}
+   |                 ^^^ required by this bound in `needs_foo`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs b/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs
new file mode 100644
index 0000000000000..15ff80ae4d953
--- /dev/null
+++ b/tests/ui/diagnostic_namespace/do_not_recommend/simple.rs
@@ -0,0 +1,23 @@
+//@ revisions: current next
+//@ ignore-compare-mode-next-solver (explicit revisions)
+//@[next] compile-flags: -Znext-solver
+
+#![feature(do_not_recommend)]
+
+trait Foo {}
+
+#[do_not_recommend]
+impl<T> Foo for T where T: Send {}
+//[current]~^ NOTE required for `*mut ()` to implement `Foo`
+//[current]~| NOTE unsatisfied trait bound introduced here
+
+fn needs_foo<T: Foo>() {}
+//~^ NOTE required by a bound in `needs_foo`
+//~| NOTE required by this bound in `needs_foo`
+
+fn main() {
+    needs_foo::<*mut ()>();
+    //~^ ERROR the trait bound `*mut (): Foo` is not satisfied
+    //[current]~| NOTE the trait `Send` is not implemented for `*mut ()`
+    //[next]~| NOTE the trait `Foo` is not implemented for `*mut ()`
+}

From 50338aa59a2fe945f3f89cd72e0377f5b6a03d25 Mon Sep 17 00:00:00 2001
From: Michael Goulet <michael@errs.io>
Date: Sat, 4 May 2024 12:57:01 -0400
Subject: [PATCH 09/16] Record impl args in the proof tree

---
 .../src/solve/eval_ctxt/mod.rs                |  8 +++++--
 .../diagnostics/point-at-failing-nested.rs    | 24 +++++++++++++++++++
 .../point-at-failing-nested.stderr            | 23 ++++++++++++++++++
 3 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.rs
 create mode 100644 tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.stderr

diff --git a/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
index bae1c6b60115e..773babde0d7b3 100644
--- a/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
+++ b/compiler/rustc_trait_selection/src/solve/eval_ctxt/mod.rs
@@ -888,8 +888,12 @@ impl<'tcx> EvalCtxt<'_, 'tcx> {
         self.infcx.resolve_vars_if_possible(value)
     }
 
-    pub(super) fn fresh_args_for_item(&self, def_id: DefId) -> ty::GenericArgsRef<'tcx> {
-        self.infcx.fresh_args_for_item(DUMMY_SP, def_id)
+    pub(super) fn fresh_args_for_item(&mut self, def_id: DefId) -> ty::GenericArgsRef<'tcx> {
+        let args = self.infcx.fresh_args_for_item(DUMMY_SP, def_id);
+        for arg in args {
+            self.inspect.add_var_value(arg);
+        }
+        args
     }
 
     pub(super) fn translate_args(
diff --git a/tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.rs b/tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.rs
new file mode 100644
index 0000000000000..840a4eb648c59
--- /dev/null
+++ b/tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.rs
@@ -0,0 +1,24 @@
+//@ compile-flags: -Znext-solver
+
+trait Foo {}
+trait Bar {}
+trait Constrain {
+    type Output;
+}
+
+impl<T, U> Foo for T
+where
+    T: Constrain<Output = U>,
+    U: Bar,
+{
+}
+
+impl Constrain for () {
+    type Output = ();
+}
+
+fn needs_foo<T: Foo>() {}
+fn main() {
+    needs_foo::<()>();
+    //~^ the trait bound `(): Foo` is not satisfied
+}
diff --git a/tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.stderr b/tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.stderr
new file mode 100644
index 0000000000000..6bf4e3cb53493
--- /dev/null
+++ b/tests/ui/traits/next-solver/diagnostics/point-at-failing-nested.stderr
@@ -0,0 +1,23 @@
+error[E0277]: the trait bound `(): Foo` is not satisfied
+  --> $DIR/point-at-failing-nested.rs:22:17
+   |
+LL |     needs_foo::<()>();
+   |                 ^^ the trait `Bar` is not implemented for `()`, which is required by `(): Foo`
+   |
+note: required for `()` to implement `Foo`
+  --> $DIR/point-at-failing-nested.rs:9:12
+   |
+LL | impl<T, U> Foo for T
+   |            ^^^     ^
+...
+LL |     U: Bar,
+   |        --- unsatisfied trait bound introduced here
+note: required by a bound in `needs_foo`
+  --> $DIR/point-at-failing-nested.rs:20:17
+   |
+LL | fn needs_foo<T: Foo>() {}
+   |                 ^^^ required by this bound in `needs_foo`
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0277`.

From 79e09a6fc551760379093cb482078f55530bd7af Mon Sep 17 00:00:00 2001
From: Vladimir Makaev <vmakaev@gmail.com>
Date: Sat, 4 May 2024 17:55:19 +0000
Subject: [PATCH 10/16] Added an entry for "lldb" in config.example.toml

---
 config.example.toml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/config.example.toml b/config.example.toml
index 5c1fac7672a9a..3b76952504f28 100644
--- a/config.example.toml
+++ b/config.example.toml
@@ -254,6 +254,10 @@
 # executing the debuginfo test suite.
 #gdb = "gdb"
 
+# The path to (or name of) the LLDB executable to use. This is only used for
+# executing the debuginfo test suite.
+#lldb = "lldb"
+
 # The node.js executable to use. Note that this is only used for the emscripten
 # target when running tests, otherwise this can be omitted.
 #nodejs = "node"

From 86a933a5743afe4117fdde5bdf04ba1baa634715 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 4 May 2024 19:59:11 +0200
Subject: [PATCH 11/16] interpret: Drop: always evaluate place

---
 compiler/rustc_const_eval/src/interpret/terminator.rs | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/compiler/rustc_const_eval/src/interpret/terminator.rs b/compiler/rustc_const_eval/src/interpret/terminator.rs
index 07425f9a6865c..cc9c7cbc0b04a 100644
--- a/compiler/rustc_const_eval/src/interpret/terminator.rs
+++ b/compiler/rustc_const_eval/src/interpret/terminator.rs
@@ -169,10 +169,8 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
             }
 
             Drop { place, target, unwind, replace: _ } => {
-                let frame = self.frame();
-                let ty = place.ty(&frame.body.local_decls, *self.tcx).ty;
-                let ty = self.instantiate_from_frame_and_normalize_erasing_regions(frame, ty)?;
-                let instance = Instance::resolve_drop_in_place(*self.tcx, ty);
+                let place = self.eval_place(place)?;
+                let instance = Instance::resolve_drop_in_place(*self.tcx, place.layout.ty);
                 if let ty::InstanceDef::DropGlue(_, None) = instance.def {
                     // This is the branch we enter if and only if the dropped type has no drop glue
                     // whatsoever. This can happen as a result of monomorphizing a drop of a
@@ -181,8 +179,7 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
                     self.go_to_block(target);
                     return Ok(());
                 }
-                let place = self.eval_place(place)?;
-                trace!("TerminatorKind::drop: {:?}, type {}", place, ty);
+                trace!("TerminatorKind::drop: {:?}, type {}", place, place.layout.ty);
                 self.drop_in_place(&place, instance, target, unwind)?;
             }
 

From f0dee6bbe5f093ce4fc40c33ad13b0b1350df7f5 Mon Sep 17 00:00:00 2001
From: Ralf Jung <post@ralfj.de>
Date: Sat, 4 May 2024 20:04:01 +0200
Subject: [PATCH 12/16] some comments or dynamic drop handling

---
 compiler/rustc_codegen_ssa/src/mir/block.rs           | 4 ++--
 compiler/rustc_const_eval/src/interpret/terminator.rs | 6 ++++++
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/compiler/rustc_codegen_ssa/src/mir/block.rs b/compiler/rustc_codegen_ssa/src/mir/block.rs
index be5458523d1ca..26e429034dca6 100644
--- a/compiler/rustc_codegen_ssa/src/mir/block.rs
+++ b/compiler/rustc_codegen_ssa/src/mir/block.rs
@@ -540,7 +540,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     //                \-------/
                     //
                     let virtual_drop = Instance {
-                        def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0),
+                        def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0), // idx 0: the drop function
                         args: drop_fn.args,
                     };
                     debug!("ty = {:?}", ty);
@@ -581,7 +581,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                     //
                     // SO THEN WE CAN USE THE ABOVE CODE.
                     let virtual_drop = Instance {
-                        def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0),
+                        def: ty::InstanceDef::Virtual(drop_fn.def_id(), 0), // idx 0: the drop function
                         args: drop_fn.args,
                     };
                     debug!("ty = {:?}", ty);
diff --git a/compiler/rustc_const_eval/src/interpret/terminator.rs b/compiler/rustc_const_eval/src/interpret/terminator.rs
index cc9c7cbc0b04a..b474003087ba3 100644
--- a/compiler/rustc_const_eval/src/interpret/terminator.rs
+++ b/compiler/rustc_const_eval/src/interpret/terminator.rs
@@ -949,6 +949,12 @@ impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
         // implementation fail -- a problem shared by rustc.
         let place = self.force_allocation(place)?;
 
+        // We behave a bit different from codegen here.
+        // Codegen creates an `InstanceDef::Virtual` with index 0 (the slot of the drop method) and
+        // then dispatches that to the normal call machinery. However, our call machinery currently
+        // only supports calling `VtblEntry::Method`; it would choke on a `MetadataDropInPlace`. So
+        // instead we do the virtual call stuff ourselves. It's easier here than in `eval_fn_call`
+        // since we can just get a place of the underlying type and use `mplace_to_ref`.
         let place = match place.layout.ty.kind() {
             ty::Dynamic(data, _, ty::Dyn) => {
                 // Dropping a trait object. Need to find actual drop fn.

From 7dc27d596b36d81d1aff4d917cfef0771acef0b9 Mon Sep 17 00:00:00 2001
From: Ian Douglas Scott <ian@iandouglasscott.com>
Date: Sat, 4 May 2024 11:11:46 -0700
Subject: [PATCH 13/16] library/std: Fix build for NetBSD targets with 32-bit
 `c_long`

This fixes building `std` for targets like `mipsel-unknown-netbsd`.

If `c_long` is an `i64`, this conversion works with `Into`. But if it's
an `i32`, this failed to convert a `u32` to an `i32`.
---
 library/std/src/sys/pal/unix/thread_parking.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/library/std/src/sys/pal/unix/thread_parking.rs b/library/std/src/sys/pal/unix/thread_parking.rs
index 66ffc0060574d..1366410b71edc 100644
--- a/library/std/src/sys/pal/unix/thread_parking.rs
+++ b/library/std/src/sys/pal/unix/thread_parking.rs
@@ -5,7 +5,7 @@
 use crate::ffi::{c_int, c_void};
 use crate::ptr;
 use crate::time::Duration;
-use libc::{_lwp_self, clockid_t, lwpid_t, time_t, timespec, CLOCK_MONOTONIC};
+use libc::{_lwp_self, c_long, clockid_t, lwpid_t, time_t, timespec, CLOCK_MONOTONIC};
 
 extern "C" {
     fn ___lwp_park60(
@@ -38,7 +38,7 @@ pub fn park_timeout(dur: Duration, hint: usize) {
         // Saturate so that the operation will definitely time out
         // (even if it is after the heat death of the universe).
         tv_sec: dur.as_secs().try_into().ok().unwrap_or(time_t::MAX),
-        tv_nsec: dur.subsec_nanos().into(),
+        tv_nsec: dur.subsec_nanos() as c_long,
     };
 
     // Timeout needs to be mutable since it is modified on NetBSD 9.0 and

From eade8365b1b6aff3404de4d5e39818482169de29 Mon Sep 17 00:00:00 2001
From: Barrett <onkoe@protonmail.com>
Date: Sat, 4 May 2024 13:28:25 -0500
Subject: [PATCH 14/16] docs(fix): incorrect Hermit links in the rustc book

the Hermit team seems to have moved from `hermitcore` to
`hermit-os` on GitHub. this change corrects the old links on its
target page.
---
 src/doc/rustc/src/platform-support/hermit.md | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/doc/rustc/src/platform-support/hermit.md b/src/doc/rustc/src/platform-support/hermit.md
index 146079e36f44c..d3d74fb1bd936 100644
--- a/src/doc/rustc/src/platform-support/hermit.md
+++ b/src/doc/rustc/src/platform-support/hermit.md
@@ -4,7 +4,7 @@
 
 The [Hermit] unikernel target allows compiling your applications into self-contained, specialized unikernel images that can be run in small virtual machines.
 
-[Hermit]: https://github.com/hermitcore
+[Hermit]: https://github.com/hermit-os
 
 Target triplets available so far:
 
@@ -58,7 +58,7 @@ To compile for these targets, you will either need to build Rust with the target
 
 Building Rust programs can be done by following the tutorial in our starter application [rusty-demo].
 
-[rusty-demo]: https://github.com/hermitcore/rusty-demo
+[rusty-demo]: https://github.com/hermit-os/rusty-demo
 
 ## Testing
 
@@ -67,8 +67,8 @@ These images can be chainloaded by Hermit's [loader] or hypervisor ([Uhyve]).
 QEMU can be used to boot Hermit binaries using the loader on any architecture.
 The targets do not support running the Rust test suite.
 
-[loader]: https://github.com/hermitcore/rusty-loader
-[Uhyve]: https://github.com/hermitcore/uhyve
+[loader]: https://github.com/hermit-os/hermit-rs-template
+[Uhyve]: https://github.com/hermit-os/uhyve
 
 ## Cross-compilation toolchains and C code
 

From da961a8b928e96d719117c9409fd6099efc06cff Mon Sep 17 00:00:00 2001
From: Barrett <onkoe@protonmail.com>
Date: Sat, 4 May 2024 13:39:38 -0500
Subject: [PATCH 15/16] fix(docs): Correct Hermit links to loader +
 'rusty-demo'
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Both are renamed! Sorry for the initial incorrect commit,
but this should correct it. 😄
---
 src/doc/rustc/src/platform-support/hermit.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/doc/rustc/src/platform-support/hermit.md b/src/doc/rustc/src/platform-support/hermit.md
index d3d74fb1bd936..9aada469acc6c 100644
--- a/src/doc/rustc/src/platform-support/hermit.md
+++ b/src/doc/rustc/src/platform-support/hermit.md
@@ -56,9 +56,9 @@ Rust does not yet ship pre-compiled artifacts for these targets.
 To compile for these targets, you will either need to build Rust with the targets enabled
 (see “Building the targets” above), or build your own copy of `core` by using `build-std` or similar.
 
-Building Rust programs can be done by following the tutorial in our starter application [rusty-demo].
+Building Rust programs can be done by following the tutorial in our starter application [hermit-rs-template].
 
-[rusty-demo]: https://github.com/hermit-os/rusty-demo
+[hermit-rs-template]: https://github.com/hermit-os/hermit-rs-template
 
 ## Testing
 
@@ -67,7 +67,7 @@ These images can be chainloaded by Hermit's [loader] or hypervisor ([Uhyve]).
 QEMU can be used to boot Hermit binaries using the loader on any architecture.
 The targets do not support running the Rust test suite.
 
-[loader]: https://github.com/hermit-os/hermit-rs-template
+[loader]: https://github.com/hermit-os/loader
 [Uhyve]: https://github.com/hermit-os/uhyve
 
 ## Cross-compilation toolchains and C code

From 3abefa17fbd05cdb8868c9256b3374f34fae4ab4 Mon Sep 17 00:00:00 2001
From: barrett <66580279+onkoe@users.noreply.github.com>
Date: Sat, 4 May 2024 14:53:08 -0500
Subject: [PATCH 16/16] docs(hermit): Explain Hermit's template link

Co-authored-by: Jubilee <46493976+workingjubilee@users.noreply.github.com>
---
 src/doc/rustc/src/platform-support/hermit.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/doc/rustc/src/platform-support/hermit.md b/src/doc/rustc/src/platform-support/hermit.md
index 9aada469acc6c..5aa787e53e1eb 100644
--- a/src/doc/rustc/src/platform-support/hermit.md
+++ b/src/doc/rustc/src/platform-support/hermit.md
@@ -56,7 +56,7 @@ Rust does not yet ship pre-compiled artifacts for these targets.
 To compile for these targets, you will either need to build Rust with the targets enabled
 (see “Building the targets” above), or build your own copy of `core` by using `build-std` or similar.
 
-Building Rust programs can be done by following the tutorial in our starter application [hermit-rs-template].
+As all Hermit programs are unikernels, building a Rust program also requires including the operating system code. A guide for doing so is provided in our starter [hermit-rs-template].
 
 [hermit-rs-template]: https://github.com/hermit-os/hermit-rs-template