feat: update depot version to 0.12.2 and add support for custom linker and preprocessor flags

src/builder/mod.rs

@@ -189,6 +189,12 @@ pub fn standard_build_env(
             set_env_var(&mut env_vars, "CC", flags.cc.clone());
             set_env_var(&mut env_vars, "CXX", flags.cxx.clone());
             set_env_var(&mut env_vars, "AR", flags.ar.clone());
+            if !flags.ld.trim().is_empty() {
+                set_env_var(&mut env_vars, "LD", flags.ld.clone());
+            }
+            if !flags.cpp.trim().is_empty() {
+                set_env_var(&mut env_vars, "CPP", flags.cpp.clone());
+            }
         }
     }
 
@@ -448,6 +454,17 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_standard_build_env_exports_native_linker_and_cpp() {
+        let mut spec = mk_spec(Vec::new(), Vec::new());
+        spec.build.flags.ld = "ld.lld".to_string();
+        spec.build.flags.cpp = "clang-cpp".to_string();
+
+        let env = standard_build_env(&spec, None, true, true);
+        assert!(env.iter().any(|(k, v)| k == "LD" && v == "ld.lld"));
+        assert!(env.iter().any(|(k, v)| k == "CPP" && v == "clang-cpp"));
+    }
+
     #[test]
     fn test_standard_build_env_respects_export_compiler_flags_toggle() {
         let mut spec = mk_spec(vec!["-O2"], vec!["-Wl,--as-needed"]);