diff --git a/build.rs b/build.rs
index e60672a76133b..9aa8e4a7e96fd 100644
--- a/build.rs
+++ b/build.rs
@@ -181,6 +181,11 @@ fn rustc_minor_nightly() -> (u32, bool) {
         .output()
         .ok()
         .expect("Failed to get rustc version");
+    if !output.status.success() {
+        let stderr = std::string::String::from_utf8_lossy(output.stderr.as_slice());
+        eprintln!("failed to run rustc: {stderr}");
+    }
+
     let version = otry!(str::from_utf8(&output.stdout).ok());
     let mut pieces = version.split('.');