From a8658fe0ccbefc68be96058bf2c8d8c08f25fdc9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Kr=C3=B6ning?=
 <martin.kroening@eonerc.rwth-aachen.de>
Date: Fri, 11 Oct 2024 10:13:22 +0200
Subject: [PATCH] fix(build.rs): keep `CARGO_HOME` and `RUSTUP_HOME`
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Signed-off-by: Martin Kröning <martin.kroening@eonerc.rwth-aachen.de>
---
 rftrace/build.rs | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/rftrace/build.rs b/rftrace/build.rs
index 15f0a5a..b560168 100755
--- a/rftrace/build.rs
+++ b/rftrace/build.rs
@@ -90,9 +90,13 @@ fn main() {
 
 /// Returns the Rustup proxy for Cargo.
 // Adapted from Hermit.
-fn cargo() -> Command {
-    let cargo = {
-        let exe = format!("cargo{}", env::consts::EXE_SUFFIX);
+pub fn cargo() -> Command {
+    sanitize("cargo")
+}
+
+fn sanitize(cmd: &str) -> Command {
+    let cmd = {
+        let exe = format!("{cmd}{}", env::consts::EXE_SUFFIX);
         // On windows, the userspace toolchain ends up in front of the rustup proxy in $PATH.
         // To reach the rustup proxy nonetheless, we explicitly query $CARGO_HOME.
         let mut cargo_home = PathBuf::from(env::var_os("CARGO_HOME").unwrap());
@@ -105,17 +109,22 @@ fn cargo() -> Command {
         }
     };
 
-    let mut cargo = Command::new(cargo);
+    let mut cmd = Command::new(cmd);
+
+    cmd.current_dir(env::var_os("CARGO_MANIFEST_DIR").unwrap());
 
     // Remove rust-toolchain-specific environment variables from kernel cargo
-    cargo.env_remove("LD_LIBRARY_PATH");
+    cmd.env_remove("LD_LIBRARY_PATH");
     env::vars()
-        .filter(|(key, _value)| key.starts_with("CARGO") || key.starts_with("RUST"))
+        .filter(|(key, _value)| {
+            key.starts_with("CARGO") && !key.starts_with("CARGO_HOME")
+                || key.starts_with("RUST") && !key.starts_with("RUSTUP_HOME")
+        })
         .for_each(|(key, _value)| {
-            cargo.env_remove(&key);
+            cmd.env_remove(&key);
         });
 
-    cargo
+    cmd
 }
 
 /// Makes all internal symbols private to avoid duplicated symbols.