Try something random

Author: jieyouxu

src/tools/run-make-support/src/lib.rs

@@ -111,7 +111,9 @@ fn run_common(bin_name: &str) -> (Command, Output) {
 
     if target.contains("windows") {
         let mut path = std::env::var("PATH").unwrap_or(String::new());
-        path.push(':');
+        if !path.is_empty() {
+            path.push(':');
+        }
         path.push_str(&std::env::var("TARGET_RPATH_DIR").unwrap());
         cmd.env("PATH", &path);
     }