From 56454051606bb010e02426bfea3329aefe0b85b9 Mon Sep 17 00:00:00 2001
From: jyn <github@jyn.dev>
Date: Sat, 9 Dec 2023 11:49:07 -0500
Subject: [PATCH] workaround cargo bugs on windows

---
 src/bootstrap/src/bin/rustc.rs    | 9 +++++++--
 src/bootstrap/src/core/builder.rs | 4 ++++
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/src/bootstrap/src/bin/rustc.rs b/src/bootstrap/src/bin/rustc.rs
index 7ca6a78bb509f..649940ac3fbbd 100644
--- a/src/bootstrap/src/bin/rustc.rs
+++ b/src/bootstrap/src/bin/rustc.rs
@@ -16,7 +16,7 @@
 //! never get replaced.
 
 use std::env;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::{Child, Command};
 use std::time::Instant;
 
@@ -85,7 +85,12 @@ fn main() {
     } else {
         // Cargo doesn't respect RUSTC_WRAPPER for version information >:(
         // don't remove the first arg if we're being run as RUSTC instead of RUSTC_WRAPPER.
-        if args[0] == env::current_exe().expect("couldn't get path to rustc shim") {
+        // Cargo also sometimes doesn't pass the `.exe` suffix on Windows - add it manually.
+        let current_exe = env::current_exe().expect("couldn't get path to rustc shim");
+        // NOTE: we intentionally pass the name of the host, not the target.
+        let host = env::var("CFG_COMPILER_BUILD_TRIPLE").unwrap();
+        let arg0 = exe(args[0].to_str().expect("only utf8 paths are supported"), &host);
+        if Path::new(&arg0) == current_exe {
             args.remove(0);
         }
         rustc_real
diff --git a/src/bootstrap/src/core/builder.rs b/src/bootstrap/src/core/builder.rs
index b3a77383b5690..43d9a14661c37 100644
--- a/src/bootstrap/src/core/builder.rs
+++ b/src/bootstrap/src/core/builder.rs
@@ -2014,7 +2014,11 @@ impl<'a> Builder<'a> {
         // Environment variables *required* throughout the build
         //
         // FIXME: should update code to not require this env var
+
+        // The host this new compiler will *run* on.
         cargo.env("CFG_COMPILER_HOST_TRIPLE", target.triple);
+        // The host this new compiler is being *built* on.
+        cargo.env("CFG_COMPILER_BUILD_TRIPLE", compiler.host.triple);
 
         // Set this for all builds to make sure doc builds also get it.
         cargo.env("CFG_RELEASE_CHANNEL", &self.config.channel);