test: Fix tox v4 and rustup interaction

ravenexp · ravenexp · commit e1d3111bd96d · 2023-03-14T11:44:48.000+03:00
Ensure that `RUSTUP_HOME` environment variable is passed through
to the isolated build environments used by `tox`.
diff --git a/tox.ini b/tox.ini
@@ -2,6 +2,10 @@
 envlist = py3
 isolated_build = True
 
+[pkgenv]
+pass_env = RUSTUP_HOME
+
 [testenv]
+pass_env = RUSTUP_HOME
 deps = pytest
 commands = pytest --verbose
