timeout: Fix performance regression using sigtimedwait

.github/workflows/test-timeout-macos.yml

@@ -0,0 +1,27 @@
+name: Test Timeout on macOS
+
+on:
+  push:
+    branches:
+      - fix-timeout-performance
+  workflow_dispatch:
+
+jobs:
+  test-macos:
+    runs-on: macos-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install Rust
+        uses: dtolnay/rust-toolchain@stable  # spell-checker:ignore dtolnay
+
+      - name: Build timeout
+        run: cargo build --release -p uu_timeout
+
+      - name: Run timeout tests
+        run: cargo test --test tests test_timeout -- --nocapture  # spell-checker:ignore nocapture
+
+      - name: Test overflow case directly
+        run: |
+          ./target/release/timeout 9223372036854775808d sleep 0
+          echo "Exit code: $?"

src/uu/timeout/Cargo.toml

@@ -20,7 +20,7 @@ path = "src/timeout.rs"
 [dependencies]
 clap = { workspace = true }
 libc = { workspace = true }
-nix = { workspace = true, features = ["signal"] }
+nix = { workspace = true, features = ["signal", "event"] }
 uucore = { workspace = true, features = ["parser", "process", "signals"] }
 fluent = { workspace = true }