193 fix macos installation from crates (#194)

* remove build instructions from cargo toml

* added mac specific linker args to build.rs

* bump version

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "ggetrs"
-version = "0.1.76"
+version = "0.1.77"
 edition = "2021"
 license = "MIT"
 description = "Efficient querying of biological databases from the command line"
@@ -35,15 +35,3 @@ serde = { version = "1.0.144", features = ["derive"] }
 serde-xml-rs = "0.6.0"
 serde_json = "1.0.85"
 tokio = { version = "1.21.0", features = ["full"] }
-
-# Build instructions of MacOS
-[target.aarch64-apple-darwin]
-rustflags = [
-  "-C", "link-arg=-undefined",
-  "-C", "link-arg=dynamic_lookup",
-]
-[target.x86_64-apple-darwin]
-rustflags = [
-  "-C", "link-arg=-undefined",
-  "-C", "link-arg=dynamic_lookup",
-]

build.rs

@@ -0,0 +1,9 @@
+use std::env;
+
+fn main() {
+    let target_os = env::var("CARGO_CFG_TARGET_OS").unwrap();
+    if target_os == "macos" {
+        println!("cargo:rustc-link-arg=-undefined");
+        println!("cargo:rustc-link-arg=dynamic_lookup");
+    }
+}