From 2957b27600883604449ef9adda835d3a49d18a9c Mon Sep 17 00:00:00 2001
From: robobun <117481402+robobun@users.noreply.github.com>
Date: Wed, 12 Aug 2026 03:03:41 +0000
Subject: [PATCH] ci(darwin tart): export RUSTUP_HOME/CARGO_HOME in the guest
 job environment

bootstrap.sh installs rustup into /opt/rust and exports RUSTUP_HOME and
CARGO_HOME from the login profile. job.sh runs as a plain /bin/bash script,
so it only had /opt/rust/bin on PATH: the rustup proxies resolved but looked
for a toolchain in ~/.rustup, and every cargo invocation in a test job failed
with "rustup could not choose a version of cargo to run". This made
test/js/third_party/grpc-js/test-tonic.test.ts fail on every run of the
darwin previous-tier (tart) lane.
---
 scripts/darwin-ci/guest/job.sh | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/scripts/darwin-ci/guest/job.sh b/scripts/darwin-ci/guest/job.sh
index 051fb3d824ac..3545ac487f10 100755
--- a/scripts/darwin-ci/guest/job.sh
+++ b/scripts/darwin-ci/guest/job.sh
@@ -2,6 +2,9 @@
 # Runs inside the per-job guest. Expects ~/job.env (exported by the command hook) and the checkout at ~/work.
 set -u
 export PATH=/usr/local/bin:/opt/homebrew/bin:/opt/rust/bin:$PATH
+# bootstrap.sh installs rustup into /opt/rust and only exports these from the login profile, which this script
+# does not source; without them the proxies in /opt/rust/bin look for a toolchain in ~/.rustup and find none.
+export RUSTUP_HOME=/opt/rust CARGO_HOME=/opt/rust
 export BUILDKITE_BUILD_CHECKOUT_PATH=$HOME/work
 set -a; source ~/job.env; set +a
 cd ~/work