build: add default brew libarchive path on macos

On macos brew installs libarchive.pc file not into the default path.
Manually setting the ENV before being able to use cargo ... or esp.
vs code "test"/"debug" features is a pain.
So adding this workaround.

src/build.rs

@@ -8,6 +8,22 @@ fn main() {
 
 #[cfg(not(target_env = "msvc"))]
 fn find_libarchive() {
+    const MACOS_HOMEBREW_LIBARCHIVE_PATH: &str = "/opt/homebrew/opt/libarchive/lib/pkgconfig/";
+
+    if cfg!(target_os = "macos")
+        && pkg_config::Config::new()
+            .atleast_version("3.2.0")
+            .probe("libarchive")
+            .is_err()
+        && std::path::Path::new(MACOS_HOMEBREW_LIBARCHIVE_PATH).exists()
+    {
+        // on OSX brew doesn't install libarchive in the default path...
+        // try that workaround as it's a pain providing this in the env e.g.
+        // for vs code usage.
+        // todo should add to current one and set afterwards to current value!
+        std::env::set_var("PKG_CONFIG_PATH", MACOS_HOMEBREW_LIBARCHIVE_PATH);
+    }
+
     pkg_config::Config::new()
         .atleast_version("3.2.0")
         .probe("libarchive")