From b362df0c4227ad0109df3e67b0ca6c1384d2bc30 Mon Sep 17 00:00:00 2001
From: Jake Lishman <jake.lishman@ibm.com>
Date: Fri, 26 Jul 2024 22:03:52 +0100
Subject: [PATCH] Allow overriding Rust toolchain in `tox` runs (#12827)

It can be convenient to use different versions of the Rust toolchain for
various `tox` runs.  This can already be done externally to `tox`
by a stateful `rustup override set <x>` followed by clearing the
override after the tox run, but allowing the environment variable to
pass through lets it be localised to just a single run.
---
 tox.ini | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tox.ini b/tox.ini
index 3ee544538a09..89dc84d1758a 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,6 +16,7 @@ setenv =
   QISKIT_TEST_CAPTURE_STREAMS=1
   QISKIT_PARALLEL=FALSE
 passenv = 
+  RUSTUP_TOOLCHAIN
   RAYON_NUM_THREADS
   OMP_NUM_THREADS
   QISKIT_PARALLEL