--- /dev/null
+--- a/src/bootstrap/bootstrap.py
++++ b/src/bootstrap/bootstrap.py
+@@ -543,7 +543,7 @@ class RustBuild(object):
+ shutil.rmtree(bin_root)
+
+ key = self.stage0_compiler.date
+- cache_dst = os.path.join(self.build_dir, "cache")
++ cache_dst = os.getenv('OPENWRT_RUSTC_BOOTSTRAP_CACHE', os.path.join(self.build_dir, "cache"))
+ rustc_cache = os.path.join(cache_dst, key)
+ if not os.path.exists(rustc_cache):
+ os.makedirs(rustc_cache)
+--- a/src/bootstrap/download.rs
++++ b/src/bootstrap/download.rs
+@@ -507,7 +507,10 @@ impl Config {
+ key: &str,
+ destination: &str,
+ ) {
+- let cache_dst = self.out.join("cache");
++ let cache_dst = match env::var_os("OPENWRT_RUSTC_BOOTSTRAP_CACHE") {
++ Some(v) => PathBuf::from(v),
++ None => self.out.join("cache"),
++ };
+ let cache_dir = cache_dst.join(key);
+ if !cache_dir.exists() {
+ t!(fs::create_dir_all(&cache_dir));
+@@ -627,7 +630,10 @@ download-rustc = false
+ let llvm_assertions = self.llvm_assertions;
+
+ let cache_prefix = format!("llvm-{}-{}", llvm_sha, llvm_assertions);
+- let cache_dst = self.out.join("cache");
++ let cache_dst = match env::var_os("OPENWRT_RUSTC_BOOTSTRAP_CACHE") {
++ Some(v) => PathBuf::from(v),
++ None => self.out.join("cache"),
++ };
+ let rustc_cache = cache_dst.join(cache_prefix);
+ if !rustc_cache.exists() {
+ t!(fs::create_dir_all(&rustc_cache));