diagnostics: let the caret rendering be compiled out

The renderer and its ariadne dependency sit behind the new
feat_diagnostics cargo feature, on by default. Without it a no-op
stand-in with the same API takes uucore::diagnostics' place, so the
utilities need no cfg of their own: enabled() is always false and
every caller falls back to its plain one-line message.

Each utility keeps a crate-level `diagnostics` feature for standalone
builds, the caret snapshot tests compile out with the renderer, and CI
gains a Build/No-diagnostics job that runs the suite without the
feature and fails if ariadne sneaks back into the dependency tree.

.github/workflows/CICD.yml

@@ -901,6 +901,50 @@ jobs:
           --features "${{ matrix.job.features }},openssl" \
           -E 'test(/^test_(md5sum|sha1sum|sha224sum|sha256sum|sha384sum|sha512sum|cksum)::/)'
 
+  test_no_diagnostics:
+    name: Build/No-diagnostics
+    needs: [ min_version, deps ]
+    runs-on: ubuntu-latest
+    timeout-minutes: 60
+    steps:
+    - uses: actions/checkout@v7
+      with:
+        persist-credentials: false
+    - uses: dtolnay/rust-toolchain@stable
+    - uses: taiki-e/install-action@nextest
+    - uses: Swatinem/rust-cache@v2
+    - name: Run sccache-cache
+      id: sccache-setup
+      uses: mozilla-actions/sccache-action@v0.0.11
+      continue-on-error: true
+    - name: Export sccache
+      if: steps.sccache-setup.outcome == 'success'
+      run: |
+        echo "RUSTC_WRAPPER=sccache" >> $GITHUB_ENV
+        echo "SCCACHE_GHA_ENABLED=true" >> $GITHUB_ENV
+    # The caret diagnostics (`feat_diagnostics`) are on by default; packagers
+    # who want the smaller dependency tree build with them off, so that build
+    # must stay green. The caret snapshot tests are gated on the feature and
+    # compile out; everything else runs as usual against the plain messages.
+    - name: Test without the diagnostics feature
+      shell: bash
+      env:
+        RUST_BACKTRACE: "1"
+      run: |
+        cargo nextest run --hide-progress-bar --profile ci \
+          --no-default-features --features feat_os_unix
+    # Confirm the feature actually compiles the renderer out. If ariadne is
+    # still in the tree, some crate re-grew a hard dependency on it.
+    # (`cargo tree -i` exits non-zero when the crate is absent from the graph.)
+    - name: Verify ariadne is compiled out
+      shell: bash
+      run: |
+        if cargo tree -p coreutils --no-default-features --features feat_os_unix -e normal -i ariadne 2>/dev/null; then
+          echo "ERROR: ariadne is still in the dependency tree without feat_diagnostics"
+          exit 1
+        fi
+        echo "OK: ariadne is not in the dependency tree"
+
   test_selinux:
     name: Build/SELinux
     needs: [ min_version, deps ]

.github/workflows/wasi.yml

@@ -59,6 +59,9 @@ jobs:
         # Run host-compiled integration tests against the WASI binary.
         # Tests incompatible with WASI are annotated with
         # #[cfg_attr(wasi_runner, ignore)] in the test source files.
+        # The binary above is built without default features, so it has no
+        # caret diagnostics; the host test crate does have them, hence the
+        # not(wasi_runner) in the cfg guarding every `mod diagnostics`.
         # TODO: add integration tests for these tools as WASI support is extended:
         #   arch b2sum cat cksum csplit date dir dircolors fmt join
         #   ls md5sum mkdir mv nproc pathchk pr printenv ptx pwd readlink

Cargo.toml

@@ -20,7 +20,7 @@ categories.workspace = true
 all-features = true
 
 [features]
-default = ["feat_common_core"]
+default = ["feat_common_core", "feat_diagnostics"]
 ## OS feature shortcodes
 unix = ["feat_os_unix"]
 windows = ["feat_os_windows"]
@@ -62,6 +62,15 @@ uudoc = [
   "dep:zip",
 ]
 ## features
+# "feat_diagnostics" == render errors against the argument list with a caret
+# when stderr is a terminal. On by default; build with `--no-default-features`
+# (plus a `feat_os_*` selection) to compile the rendering — and its ariadne
+# dependency — out. Utilities then keep their plain one-line messages.
+# Enabling `uucore/diagnostics` is enough: cargo unifies features, so every
+# utility in the build sees it. The matching `diagnostics` feature each `uu_*`
+# crate declares is there for building that crate on its own, and is
+# deliberately not listed here.
+feat_diagnostics = ["uucore/diagnostics"]
 ## Optional feature for stdbuf
 # "feat_external_libstdbuf" == use an external libstdbuf.so for stdbuf instead of embedding it
 feat_external_libstdbuf = ["stdbuf/feat_external_libstdbuf"]
@@ -396,6 +405,11 @@ version = "0.10.0"
 
 [workspace.dependencies]
 ansi-width = "0.1.0"
+# The diagnostics rewrite ariadne's output by row number, so a release that
+# changes the shape of a report is a breaking change here even when it is not
+# one for ariadne. `uucore`'s `the_rendered_report_has_the_row_shape_the_rewriting_assumes`
+# is what catches it; keep the bound tight enough that only patch releases
+# arrive without one running.
 ariadne = "0.6.0"
 base64-simd = "0.8"
 bigdecimal = "0.4"

fuzz/Cargo.lock

@@ -73,16 +73,6 @@ version = "1.4.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c3d036a3c4ab069c7b410a2ce876bd74808d2d0888a82667669f8e783a898bf1"
 
-[[package]]
-name = "ariadne"
-version = "0.6.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8454c8a44ce2cb9cc7e7fae67fc6128465b343b92c6631e94beca3c8d1524ea5"
-dependencies = [
- "unicode-width",
- "yansi",
-]
-
 [[package]]
 name = "arrayref"
 version = "0.3.9"
@@ -2057,7 +2047,6 @@ dependencies = [
 name = "uucore"
 version = "0.10.0"
 dependencies = [
- "ariadne",
  "base64-simd",
  "bigdecimal",
  "blake2b_simd",
@@ -2323,12 +2312,6 @@ dependencies = [
  "either",
 ]
 
-[[package]]
-name = "yansi"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfe53a6657fd280eaa890a3bc59152892ffa3e30101319d168b781ed6529b049"
-
 [[package]]
 name = "yoke"
 version = "0.8.3"

src/uu/chmod/Cargo.toml

@@ -18,18 +18,15 @@ doctest = false
 [dependencies]
 clap = { workspace = true }
 thiserror = { workspace = true }
-uucore = { workspace = true, features = [
-  "diagnostics",
-  "entries",
-  "fs",
-  "mode",
-  "perms",
-] }
+uucore = { workspace = true, features = ["entries", "fs", "mode", "perms"] }
 fluent = { workspace = true }
 
 [target.'cfg(all(unix, not(target_os = "redox")))'.dependencies]
 uucore = { workspace = true, features = ["safe-traversal"] }
 
+[features]
+diagnostics = ["uucore/diagnostics"]
+
 [lints]
 workspace = true
 

src/uu/expr/Cargo.toml

@@ -20,7 +20,7 @@ clap = { workspace = true }
 num-bigint = { workspace = true }
 num-traits = { workspace = true }
 onig = { workspace = true }
-uucore = { workspace = true, features = ["diagnostics", "i18n-collator"] }
+uucore = { workspace = true, features = ["i18n-collator"] }
 thiserror = { workspace = true }
 fluent = { workspace = true }
 
@@ -28,6 +28,9 @@ fluent = { workspace = true }
 divan = { workspace = true }
 uucore = { workspace = true, features = ["benchmark"] }
 
+[features]
+diagnostics = ["uucore/diagnostics"]
+
 [lints]
 workspace = true
 

src/uu/install/Cargo.toml

@@ -21,7 +21,6 @@ thiserror = { workspace = true }
 uucore = { workspace = true, default-features = true, features = [
   "backup-control",
   "buf-copy",
-  "diagnostics",
   "fs",
   "mode",
   "perms",
@@ -35,6 +34,7 @@ rustix = { workspace = true }
 selinux = { workspace = true, optional = true }
 
 [features]
+diagnostics = ["uucore/diagnostics"]
 selinux = ["dep:selinux", "uucore/selinux"]
 
 [lints]

src/uu/mkdir/Cargo.toml

@@ -18,18 +18,14 @@ doctest = false
 
 [dependencies]
 clap = { workspace = true }
-uucore = { workspace = true, features = [
-  "diagnostics",
-  "fs",
-  "fsxattr",
-  "mode",
-] }
+uucore = { workspace = true, features = ["fs", "fsxattr", "mode"] }
 fluent = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]
 rustix = { workspace = true, features = ["process", "fs"] }
 
 [features]
+diagnostics = ["uucore/diagnostics"]
 selinux = ["uucore/selinux"]
 smack = ["uucore/smack"]
 

src/uu/mkfifo/Cargo.toml

@@ -18,7 +18,7 @@ doctest = false
 
 [dependencies]
 clap = { workspace = true }
-uucore = { workspace = true, features = ["diagnostics", "fs", "mode"] }
+uucore = { workspace = true, features = ["fs", "mode"] }
 fluent = { workspace = true }
 
 [target.'cfg(unix)'.dependencies]
@@ -28,6 +28,7 @@ rustix = { workspace = true, features = ["fs", "process"] }
 libc = { workspace = true }
 
 [features]
+diagnostics = ["uucore/diagnostics"]
 selinux = ["uucore/selinux"]
 smack = ["uucore/smack"]
 

src/uu/mknod/Cargo.toml

@@ -19,11 +19,12 @@ doctest = false
 
 [dependencies]
 clap = { workspace = true }
-uucore = { workspace = true, features = ["diagnostics", "fs", "mode"] }
+uucore = { workspace = true, features = ["fs", "mode"] }
 fluent = { workspace = true }
 nix = { workspace = true }
 
 [features]
+diagnostics = ["uucore/diagnostics"]
 selinux = ["uucore/selinux"]
 smack = ["uucore/smack"]
 

src/uu/numfmt/Cargo.toml

@@ -17,7 +17,6 @@ path = "src/numfmt.rs"
 [dependencies]
 clap = { workspace = true }
 uucore = { workspace = true, features = [
-  "diagnostics",
   "parser",
   "ranges",
   "i18n-common",
@@ -31,6 +30,9 @@ memchr = { workspace = true }
 divan = { workspace = true }
 uucore = { workspace = true, features = ["benchmark"] }
 
+[features]
+diagnostics = ["uucore/diagnostics"]
+
 [lints]
 workspace = true
 

src/uu/printf/Cargo.toml

@@ -18,13 +18,12 @@ doctest = false
 
 [dependencies]
 clap = { workspace = true }
-uucore = { workspace = true, features = [
-  "diagnostics",
-  "format",
-  "quoting-style",
-] }
+uucore = { workspace = true, features = ["format", "quoting-style"] }
 fluent = { workspace = true }
 
+[features]
+diagnostics = ["uucore/diagnostics"]
+
 [lints]
 workspace = true
 

src/uu/sort/Cargo.toml

@@ -19,6 +19,7 @@ doctest = false
 
 [features]
 default = ["i18n-collator"]
+diagnostics = ["uucore/diagnostics"]
 i18n-collator = ["uucore/i18n-collator"]
 
 [dependencies]
@@ -34,7 +35,6 @@ self_cell = { workspace = true }
 tempfile = { workspace = true }
 thiserror = { workspace = true }
 uucore = { workspace = true, features = [
-  "diagnostics",
   "fs",
   "parser-size",
   "version-cmp",

src/uu/test/Cargo.toml

@@ -20,7 +20,7 @@ clap = { workspace = true }
 fluent = { workspace = true }
 libc = { workspace = true }
 thiserror = { workspace = true }
-uucore = { workspace = true, features = ["diagnostics", "process", "wide"] }
+uucore = { workspace = true, features = ["process", "wide"] }
 
 [target.'cfg(windows)'.dependencies]
 windows-sys = { workspace = true, features = [
@@ -33,6 +33,9 @@ windows-sys = { workspace = true, features = [
 [dev-dependencies]
 tempfile = { workspace = true }
 
+[features]
+diagnostics = ["uucore/diagnostics"]
+
 [lints]
 workspace = true
 

src/uu/tr/Cargo.toml

@@ -19,7 +19,7 @@ doctest = false
 [dependencies]
 nom = { workspace = true }
 clap = { workspace = true }
-uucore = { workspace = true, features = ["diagnostics", "fs", "signals"] }
+uucore = { workspace = true, features = ["fs", "signals"] }
 fluent = { workspace = true }
 bytecount = { workspace = true, features = ["runtime-dispatch-simd"] }
 
@@ -28,6 +28,9 @@ divan = { workspace = true }
 rustix = { workspace = true, features = ["stdio", "fs"] }
 uucore = { workspace = true, features = ["benchmark"] }
 
+[features]
+diagnostics = ["uucore/diagnostics"]
+
 [lints]
 workspace = true
 

src/uucore/Cargo.toml

@@ -175,7 +175,7 @@ i18n-datetime = [
   "jiff-icu",
   "jiff",
 ]
-mode = ["diagnostics", "libc"]
+mode = ["libc"]
 perms = ["entries", "libc", "walkdir"]
 buf-copy = []
 parser-num = ["extendedbigdecimal", "num-traits"]

src/uucore/src/lib/features.rs

@@ -19,6 +19,11 @@ pub mod checksum;
 pub mod colors;
 #[cfg(feature = "diagnostics")]
 pub mod diagnostics;
+// Without the feature, a no-op stand-in keeps the API — and its callers —
+// compiling; they all fall back to their plain one-line messages.
+#[cfg(not(feature = "diagnostics"))]
+#[path = "features/diagnostics_stub.rs"]
+pub mod diagnostics;
 #[cfg(feature = "encoding")]
 pub mod encoding;
 #[cfg(feature = "extendedbigdecimal")]

src/uucore/src/lib/features/diagnostics_stub.rs

@@ -0,0 +1,94 @@
+// This file is part of the uutils coreutils package.
+//
+// For the full copyright and license information, please view the LICENSE
+// file that was distributed with this source code.
+
+//! No-op stand-in for the `diagnostics` module, compiled when the
+//! `diagnostics` cargo feature is off.
+//!
+//! It mirrors the real API so callers need no `cfg` of their own:
+//! [`enabled`] is always `false`, the locators find nothing and the render
+//! methods render nothing, so every caller falls back to the plain one-line
+//! message it would print anywhere but a terminal.
+
+use std::ffi::{OsStr, OsString};
+use std::ops::Range;
+
+/// Always `false`: rendering is compiled out.
+pub fn enabled() -> bool {
+    false
+}
+
+/// Always `None`: rendering is compiled out.
+pub fn capture(_args: &[OsString]) -> Option<Vec<OsString>> {
+    None
+}
+
+/// Always `None`: rendering is compiled out.
+pub fn operands(_args: &[OsString]) -> Option<Vec<OsString>> {
+    None
+}
+
+/// A snapshot of nothing: it finds nothing and renders nothing.
+///
+/// Deliberately derives nothing the real `Snapshot` does not, so that what a
+/// caller may do with one does not depend on whether the feature is on.
+pub struct Snapshot;
+
+#[allow(clippy::unused_self)]
+impl Snapshot {
+    pub fn new<S: AsRef<OsStr>>(_args: &[S]) -> Self {
+        Self
+    }
+
+    pub fn with_program<S: AsRef<OsStr>>(_args: &[S]) -> Self {
+        Self
+    }
+
+    pub fn from_bytes<S: AsRef<[u8]>>(_args: &[S]) -> Self {
+        Self
+    }
+
+    pub fn is_empty(&self) -> bool {
+        true
+    }
+
+    pub fn index_of(&self, _arg: &OsStr) -> Option<usize> {
+        None
+    }
+
+    pub fn index_of_value(
+        &self,
+        _operand: &str,
+        _short: Option<char>,
+        _long: Option<&str>,
+    ) -> Option<usize> {
+        None
+    }
+
+    pub fn index_of_positional(&self, _n: usize) -> Option<usize> {
+        None
+    }
+
+    pub fn render(
+        &self,
+        _index: usize,
+        _message: &str,
+        _label: Option<&str>,
+        _help: Option<&str>,
+    ) -> bool {
+        false
+    }
+
+    pub fn render_inside_at(
+        &self,
+        _index: usize,
+        _operand: &str,
+        _range: Range<usize>,
+        _message: &str,
+        _label: Option<&str>,
+        _help: Option<&str>,
+    ) -> bool {
+        false
+    }
+}

src/uucore/src/lib/lib.rs

@@ -45,7 +45,6 @@ pub use crate::features::char_width;
 pub use crate::features::checksum;
 #[cfg(feature = "colors")]
 pub use crate::features::colors;
-#[cfg(feature = "diagnostics")]
 pub use crate::features::diagnostics;
 #[cfg(feature = "encoding")]
 pub use crate::features::encoding;

tests/by-util/test_chmod.rs

@@ -1691,6 +1691,7 @@ fn test_chmod_symlink_two_links_same_dir() {
     // cSpell:enable
 }
 
+#[cfg(all(feature = "feat_diagnostics", not(wasi_runner)))]
 mod diagnostics {
     use super::*;
     #[cfg(unix)]