From 5de06800c71c2e87fb5a2bfabc57c001f91c9cf3 Mon Sep 17 00:00:00 2001
From: 12101111 <w12101111@gmail.com>
Date: Sat, 9 Jan 2021 02:23:02 +0800
Subject: [PATCH] Don't build in-tree llvm-libunwind if system-llvm-libunwind
 is enable

---
 library/unwind/build.rs | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/library/unwind/build.rs b/library/unwind/build.rs
index fae760c4a4e6b..694e6b98c82e3 100644
--- a/library/unwind/build.rs
+++ b/library/unwind/build.rs
@@ -4,6 +4,10 @@ fn main() {
     println!("cargo:rerun-if-changed=build.rs");
     let target = env::var("TARGET").expect("TARGET was not set");
 
+    if cfg!(feature = "system-llvm-libunwind") {
+        return;
+    }
+
     if cfg!(feature = "llvm-libunwind")
         && ((target.contains("linux") && !target.contains("musl")) || target.contains("fuchsia"))
     {