step D+1: add third trivial C static lib (hello2.c)

Step D (hello.c + getauxval_fix.c) launches cleanly. E.minus-1
(hello.c + getauxval_fix.c + cpp_smoke.c) crashes. All three are
plain-C trivial single-function files.

Theory: the regression is triggered by having 3 or more cc::Build
static libs in a Tauri Android cdylib, regardless of what the libs
contain. Test: clone hello.c as hello2.c (same content, different
symbol) and add a third cc::Build step compiling it. If this crashes,
the trigger is just the number of static libs. If it launches, there's
something magical about cpp_smoke.c specifically (unlikely — it was
near-identical content).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

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()

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;
+}