fix(ci): resolve all build-rvf-node failures

Three fixes:

1. locking.rs: __errno_location is Linux-only; macOS uses __error().
   Split the extern "C" declarations by target_os so rvf-runtime
   compiles on both platforms.

2. build-rvf-node.yml: NAPI CLI outputs index.<platform>.node instead
   of rvf-node.<platform>.node. Added rename step after build.

3. build-rvf-node.yml: darwin builds need -undefined dynamic_lookup
   RUSTFLAGS so NAPI symbols resolve at runtime via Node.js.
   Added CARGO_TARGET_*_APPLE_DARWIN_RUSTFLAGS env vars.

Co-Authored-By: claude-flow <ruv@ruv.net>

.github/workflows/build-rvf-node.yml

@@ -72,10 +72,20 @@ jobs:
         run: npm install -g @napi-rs/cli@^2.18.0
 
       - name: Build rvf-node native module
+        shell: bash
         working-directory: crates/rvf/rvf-node
-        run: napi build --platform --release --target ${{ matrix.settings.target }}
+        run: |
+          napi build --platform --release --target ${{ matrix.settings.target }}
+          # NAPI CLI may output as index.<platform>.node; rename to rvf-node.<platform>.node
+          BUILT=$(ls -1 *.*.node 2>/dev/null | head -1)
+          EXPECTED="rvf-node.${{ matrix.settings.platform }}.node"
+          if [ -n "$BUILT" ] && [ "$BUILT" != "$EXPECTED" ]; then
+            mv -v "$BUILT" "$EXPECTED"
+          fi
         env:
           CARGO_TARGET_AARCH64_UNKNOWN_LINUX_GNU_LINKER: aarch64-linux-gnu-gcc
+          CARGO_TARGET_AARCH64_APPLE_DARWIN_RUSTFLAGS: "-C link-arg=-undefined -C link-arg=dynamic_lookup"
+          CARGO_TARGET_X86_64_APPLE_DARWIN_RUSTFLAGS: "-C link-arg=-undefined -C link-arg=dynamic_lookup"
 
       - name: List built artifacts
         shell: bash

crates/rvf/rvf-runtime/src/locking.rs

@@ -276,9 +276,18 @@ fn is_pid_alive(pid: u32) -> bool {
 #[cfg(unix)]
 extern "C" {
     fn kill(pid: i32, sig: i32) -> i32;
+}
+
+#[cfg(any(target_os = "linux", target_os = "android"))]
+extern "C" {
     fn __errno_location() -> *mut i32;
 }
 
+#[cfg(any(target_os = "macos", target_os = "ios", target_os = "freebsd"))]
+extern "C" {
+    fn __error() -> *mut i32;
+}
+
 /// Permission denied errno -- process exists but belongs to another user.
 #[cfg(unix)]
 const EPERM: i32 = 1;
@@ -289,11 +298,17 @@ fn libc_kill(pid: i32, sig: i32) -> i32 {
 }
 
 /// Get a pointer to the thread-local errno value.
-#[cfg(unix)]
+#[cfg(any(target_os = "linux", target_os = "android"))]
 fn libc_errno() -> *mut i32 {
     unsafe { __errno_location() }
 }
 
+/// Get a pointer to the thread-local errno value (macOS/BSD).
+#[cfg(any(target_os = "macos", target_os = "ios", target_os = "freebsd"))]
+fn libc_errno() -> *mut i32 {
+    unsafe { __error() }
+}
+
 /// Simple CRC32 (not CRC32C) for lock file checksumming.
 fn simple_crc32(data: &[u8]) -> u32 {
     let mut crc: u32 = 0xFFFFFFFF;