diff --git a/script/cargo.py b/script/cargo.py
index 0766c5f118..8ed8893272 100755
--- a/script/cargo.py
+++ b/script/cargo.py
@@ -16,8 +16,8 @@ def run_cargo(command, args):
     env = os.environ.copy()
 
     rustup_home = args.rustup_home
-    env['RUSTUP_HOME'] = rustup_home
-    env['CARGO_HOME'] = rustup_home
+    # env['RUSTUP_HOME'] = rustup_home
+    # env['CARGO_HOME'] = rustup_home
     # Enable experimental features in non-nightly builds
     env['RUSTC_BOOTSTRAP'] = '1'
 
diff --git a/script/cargo_cbindgen.py b/script/cargo_cbindgen.py
index db28fd013e..78a9dd9481 100755
--- a/script/cargo_cbindgen.py
+++ b/script/cargo_cbindgen.py
@@ -15,10 +15,10 @@ def run(args):
     env = os.environ.copy()
 
     rustup_home = args.rustup_home
-    env["RUSTUP_HOME"] = rustup_home
+    # env["RUSTUP_HOME"] = rustup_home
 
     cargo_home = args.cargo_home
-    env["CARGO_HOME"] = cargo_home
+    # env["CARGO_HOME"] = cargo_home
 
     rustup_bin = os.path.abspath(os.path.join(rustup_home, "bin"))
     cbindgen_bin = os.path.join(
diff --git a/script/download_rust_deps.py b/script/download_rust_deps.py
index 60ff491eb9..94521879c6 100755
--- a/script/download_rust_deps.py
+++ b/script/download_rust_deps.py
@@ -203,7 +203,8 @@ def main():
         "features": "vendored-openssl",
     }]
     for tool in tools:
-        cargo_install(tool, rustup_home)
+        if shutil.which(tool["name"]) is None:
+            cargo_install(tool, rustup_home)
 
     return 0