diff --git a/desktop/src-tauri/build.rs b/desktop/src-tauri/build.rs
index 84f2694..06e81be 100644
--- a/desktop/src-tauri/build.rs
+++ b/desktop/src-tauri/build.rs
@@ -32,6 +32,15 @@ fn main() {
         cc::Build::new()
             .file("cpp/getauxval_fix.c")
             .compile("getauxval_fix");
+
+        // Step D+1: identical-content clone of hello.c as a third cc::Build
+        // static library. Tests the "any 3rd static lib triggers the crash"
+        // theory in isolation — no C++, no external deps, same C content as
+        // the known-working hello.c.
+        println!("cargo:rerun-if-changed=cpp/hello2.c");
+        cc::Build::new()
+            .file("cpp/hello2.c")
+            .compile("wzp_hello2");
     }
 
     tauri_build::build()
diff --git a/desktop/src-tauri/cpp/hello2.c b/desktop/src-tauri/cpp/hello2.c
new file mode 100644
index 0000000..3636934
--- /dev/null
+++ b/desktop/src-tauri/cpp/hello2.c
@@ -0,0 +1,8 @@
+/* hello2.c — identical content to hello.c, different file name + symbol.
+ * Purpose: test if adding a THIRD trivial C static lib via cc::Build
+ * regresses Step D regardless of what's in the file. Never called from Rust. */
+#include <stdint.h>
+
+int32_t wzp_hello2_stub(void) {
+    return 43;
+}