From 9fafffd50b50f0c9132dc1098382992b8457cdbb Mon Sep 17 00:00:00 2001
From: "Felix S. Klock II" <pnkfelix@pnkfx.org>
Date: Mon, 22 Feb 2021 11:21:12 -0500
Subject: [PATCH] Print out env vars related to Rust on (sufficiently verbose)
 rustc invocations.

Fix issue 38686.

(update: placated tidy.)
---
 src/bootstrap/bin/rustc.rs | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/bootstrap/bin/rustc.rs b/src/bootstrap/bin/rustc.rs
index 3694bdbf67054..7cf4311b98578 100644
--- a/src/bootstrap/bin/rustc.rs
+++ b/src/bootstrap/bin/rustc.rs
@@ -139,6 +139,12 @@ fn main() {
     }
 
     if verbose > 1 {
+        let rust_env_vars =
+            env::vars().filter(|(k, _)| k.starts_with("RUST") || k.starts_with("CARGO"));
+        for (i, (k, v)) in rust_env_vars.enumerate() {
+            eprintln!("rustc env[{}]: {:?}={:?}", i, k, v);
+        }
+        eprintln!("rustc working directory: {}", env::current_dir().unwrap().display());
         eprintln!(
             "rustc command: {:?}={:?} {:?}",
             bootstrap::util::dylib_path_var(),