Fix unnecessary search path warning on macOS

Author: madsmtm

zng/cmake.rs

@@ -39,19 +39,19 @@ pub fn build_zlib_ng(target: &str, compat: bool) {
         cmake.define("CMAKE_GENERATOR_PLATFORM", "Win32");
     }
 
+    // libz-ng uses the GNUInstallDirs convention, so we can use the following
+    // to ensure libraries are placed in a consistent place in the
+    // installation dir.
+    cmake.define("CMAKE_INSTALL_LIBDIR", "lib");
+
     let install_dir = cmake.build();
 
     let includedir = install_dir.join("include");
     let libdir = install_dir.join("lib");
-    let libdir64 = install_dir.join("lib64");
     println!(
         "cargo:rustc-link-search=native={}",
         libdir.to_str().unwrap()
     );
-    println!(
-        "cargo:rustc-link-search=native={}",
-        libdir64.to_str().unwrap()
-    );
     let mut debug_suffix = "";
     let libname = if target.contains("windows") && target.contains("msvc") {
         if env::var("OPT_LEVEL").unwrap() == "0" {