Add intentionally buggy CI fixture crate

.gitignore

@@ -9,6 +9,9 @@ target
 /deployment
 /.idea
 
+# Cursor NAL traces (local-only; do not commit)
+.cursor/nal-trace/
+
 # Snapcraft files
 stage
 prime

Cargo.toml

@@ -48,6 +48,8 @@ members = [
   "crates/searcher",
   "crates/ignore",
 ]
+# Standalone crate for CI fixture testing (`cargo check --manifest-path ci/fixtures/...`).
+exclude = ["ci/fixtures/intentionally_buggy"]
 
 [dependencies]
 anyhow = "1.0.75"

ci/fixtures/intentionally_buggy/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "intentionally_buggy"
+version = "0.0.0"
+edition = "2024"
+publish = false
+
+[features]
+# Enable to exercise compile-failure paths in CI (e.g. `cargo check -F force_compile_error`).
+force_compile_error = []

ci/fixtures/intentionally_buggy/src/lib.rs

@@ -0,0 +1,37 @@
+//! Deliberately defective code for testing CI (lint gates, failure reporting, etc.).
+//! This crate is **not** a workspace member; build it explicitly:
+//! `cargo check --manifest-path ci/fixtures/intentionally_buggy/Cargo.toml`
+//! `cargo test --manifest-path ...` is expected to fail (see `tests::deliberate_failure`).
+
+#![warn(unused)]
+#![warn(clippy::all)]
+
+#[cfg(feature = "force_compile_error")]
+compile_error!("intentional compile_error for CI fixture testing");
+
+/// Returns `a / b`. Panics when `b == 0` — intentional logic defect.
+pub fn sloppy_div(a: i32, b: i32) -> i32 {
+    a / b
+}
+
+// Dead code: should trigger `dead_code` under `-D warnings` / strict CI.
+fn never_called() -> u32 {
+    42
+}
+
+pub fn unused_binding() -> i32 {
+    let x = 1;
+    let noise = 99; // unused variable: should warn
+    x + 2
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// CI fixture: fails on purpose so `cargo test --manifest-path ...` exits non-zero.
+    #[test]
+    fn deliberate_failure() {
+        assert_eq!(sloppy_div(10, 2), 42);
+    }
+}

tests/ci_spotcheck.rs

@@ -0,0 +1,13 @@
+//! Spot checks that only run (and fail) on selected cross targets.
+
+#[cfg(target_arch = "riscv64")]
+#[test]
+fn ci_spot_fail_riscv64() {
+    assert!(false, "intentional failure on riscv64 CI only");
+}
+
+#[cfg(target_arch = "s390x")]
+#[test]
+fn ci_spot_fail_s390x() {
+    assert!(false, "intentional failure on s390x CI only");
+}

tests/tests.rs

@@ -20,3 +20,5 @@ mod misc;
 mod multiline;
 // Regression tests.
 mod regression;
+// Fails only on riscv64 / s390x cross-test jobs (see ci_spotcheck.rs).
+mod ci_spotcheck;