diff --git a/crates/oaknode/src/nodes/timeformat.rs b/crates/oaknode/src/nodes/timeformat.rs
index 1caaa139f..7ab51915c 100644
--- a/crates/oaknode/src/nodes/timeformat.rs
+++ b/crates/oaknode/src/nodes/timeformat.rs
@@ -82,6 +82,31 @@ extern "C" {
 	fn _gmtime64_s(result: *mut Tm, timep: *const i64) -> i32;
 }
 
+/// Split epoch seconds into calendar fields through the C library — local
+/// time when `local` is set, UTC otherwise (C++ `localtime_r`/`gmtime_r`).
+/// Shared by `value()` and its test so both stay on the same cfg-gated FFI.
+fn break_down_time(secs: c_long, local: bool) -> Tm {
+	let mut tm: Tm = unsafe { std::mem::zeroed() };
+	#[cfg(not(target_os = "windows"))]
+	unsafe {
+		if local {
+			localtime_r(&secs, &mut tm);
+		} else {
+			gmtime_r(&secs, &mut tm);
+		}
+	}
+	#[cfg(target_os = "windows")]
+	unsafe {
+		let secs64 = secs as i64;
+		if local {
+			_localtime64_s(&mut tm, &secs64);
+		} else {
+			_gmtime64_s(&mut tm, &secs64);
+		}
+	}
+	tm
+}
+
 /// Expand Qt date/time format tokens (`QDateTime::toString` syntax):
 /// the field tokens d/dd, M/MM, yy/yyyy, h/hh, H/HH, m/mm, s/ss, z/zz/zzz,
 /// AP/ap/A/a, and single-quoted literal sections, mirroring Qt's
@@ -295,24 +320,7 @@ impl NodeBehavior for TimeFormatNode {
 		let secs = (ms_since_epoch / 1000) as c_long;
 		let ms = (ms_since_epoch % 1000) as i32;
 
-		let mut tm: Tm = unsafe { std::mem::zeroed() };
-		#[cfg(not(target_os = "windows"))]
-		unsafe {
-			if to_bool(&local_val) {
-				localtime_r(&secs, &mut tm);
-			} else {
-				gmtime_r(&secs, &mut tm);
-			}
-		}
-		#[cfg(target_os = "windows")]
-		unsafe {
-			let secs64 = secs as i64;
-			if to_bool(&local_val) {
-				_localtime64_s(&mut tm, &secs64);
-			} else {
-				_gmtime64_s(&mut tm, &secs64);
-			}
-		}
+		let tm = break_down_time(secs, to_bool(&local_val));
 
 		let output = format_date_time(&tm, ms, &to_text(&format_val));
 		table.push(crate::value::ValueType::Text, NodeValue::Text(output), None);
@@ -547,15 +555,9 @@ mod tests {
 		// Expected values computed through the same C library calls the C++
 		// makes — this validates the routing (which function is called for
 		// each flag value), not the C library itself.
-		let mut secs: c_long = 45296;
-		let mut local: Tm = unsafe { std::mem::zeroed() };
-		unsafe {
-			localtime_r(&secs, &mut local);
-		}
-		let mut utc: Tm = unsafe { std::mem::zeroed() };
-		unsafe {
-			gmtime_r(&secs, &mut utc);
-		}
+		let secs: c_long = 45296;
+		let local = break_down_time(secs, true);
+		let utc = break_down_time(secs, false);
 		let local_expected = format!("{:04}", local.tm_year + 1900);
 		let utc_expected = format!("{:04}", utc.tm_year + 1900);
 		assert_eq!(utc_expected, "1970");
diff --git a/crates/oakrender/build.rs b/crates/oakrender/build.rs
index 8929a0aa7..e319edaac 100644
--- a/crates/oakrender/build.rs
+++ b/crates/oakrender/build.rs
@@ -19,16 +19,20 @@
 //! `-Wl,-export_dynamic` keeps the test binary's symbols in its dynamic
 //! symbol table — originally so the M12 P0 decode bridge could resolve
 //! the oakcodec C ABI with `dlsym(RTLD_DEFAULT)` (the decode bridge is a
-//! direct Rust call now, but the flag is harmless and still matches the
-//! root build.rs's app binary, M12 §0 / §5). The macOS framework flags
-//! below are the load-bearing part: the bundled OpenColorIO's system
-//! monitor references IOKit / ColorSync / CoreGraphics display APIs.
+//! direct Rust call now). It is spelled the macOS way and is therefore
+//! emitted on macOS only: on ELF platforms lld parses `-export_dynamic`
+//! as `-e xport_dynamic` and links a binary with NO entry point, which
+//! then dies with SIGSEGV inside ld.so at startup (Rust >= 1.90 links
+//! x86_64-unknown-linux-gnu with rust-lld by default). The macOS
+//! framework flags below are the load-bearing part: the bundled
+//! OpenColorIO's system monitor references IOKit / ColorSync /
+//! CoreGraphics display APIs.
 
 fn main() {
-	// Only the test binaries need this; the library itself links no
-	// dynamic symbols.
-	println!("cargo:rustc-link-arg-tests=-Wl,-export_dynamic");
 	if std::env::var("CARGO_CFG_TARGET_OS").as_deref() == Ok("macos") {
+		// Only the test binaries need this; the library itself links no
+		// dynamic symbols. (macOS-only — see the module comment.)
+		println!("cargo:rustc-link-arg-tests=-Wl,-export_dynamic");
 		// The bundled OpenColorIO's macos system monitor references
 		// IOKit / ColorSync / CoreGraphics display APIs; the engine
 		// dylib links with `-undefined,dynamic_lookup`, so test binaries