Fix cross compilation. (#601)

* Fix cross compilation.

* Add .change file.

* Update macos-crosscompile.md

Co-authored-by: Ngo Iok Ui (Wu Yu Wei) <yuweiwu@pm.me>

.changes/macos-crosscompile.md

@@ -0,0 +1,5 @@
+---
+"tao": patch
+---
+
+Support cross compiling for macos from a non macos host.

Cargo.toml

@@ -31,6 +31,9 @@ default = [ ]
 dox = [ "gtk/dox" ]
 tray = [ "libappindicator", "dirs-next" ]
 
+[build-dependencies]
+cc = "1"
+
 [dependencies]
 instant = "0.1"
 lazy_static = "1"
@@ -64,9 +67,6 @@ dispatch = "0.2"
 scopeguard = "1.1"
 png = "0.17"
 
-[target."cfg(target_os = \"macos\")".build-dependencies]
-cc = "1"
-
 [target."cfg(target_os = \"windows\")".dependencies]
 parking_lot = "0.12"
 unicode-segmentation = "1.10.0"

build.rs

@@ -12,7 +12,6 @@ fn main() {
     println!("cargo:rustc-cfg=use_colorsync_cgdisplaycreateuuidfromdisplayid");
   }
   // link carbon hotkey on macOS
-  #[cfg(target_os = "macos")]
   {
     if std::env::var("CARGO_CFG_TARGET_OS").map_or(false, |os| os == "macos") {
       println!("cargo:rustc-link-lib=framework=Carbon");