Link against shared zlib library when cross-compiling

Currently libz-sys is always building a static zlib library when cross-compiling, except on Apple platforms. Can I ask the reason of this? I have a shared zlib library in my rootfs, and pkg-config is working fine. With this config, I have a build failure because of library collision, like this:

/tmp/rustc0ZqD0F/liblibz_sys-84983a050a121d20.rlib(inflate.o): relocation R_AARCH64_ADR_PREL_PG_HI21 against symbol '__stack_chk_guard' which may bind externally can not be used when making a shared object; recompile with -fPIC

If I remove forcing this static library build, it is building fine:

index cab160ae6e6f..87e3e8664fd6 100644
--- a/build.rs
+++ b/build.rs
@@ -81,11 +81,11 @@ fn main() {
     //
     // Apple platforms have libz.1.dylib, and it's usually available even when
     // cross compiling (via fat binary or in the target's Xcode SDK)
-    let cross_compiling = target != host;
+    // let cross_compiling = target != host;
     if target.contains("msvc")
         || target.contains("pc-windows-gnu")
         || want_static
-        || (cross_compiling && !target.contains("-apple-"))
+        // || (cross_compiling && !target.contains("-apple-"))
     {
         return build_zlib(&mut cfg, &target);
     }```

Start in build.rs, especially the cross_compiling check and build_zlib call, and review how the cross-compiling branch interacts with pkg-config and a shared zlib in the target rootfs. Reproduce the reported AArch64 linking failure with the stated configuration. Done means the intended shared-versus-static behavior is resolved for cross-compilation without the reported library collision.