From a8461559c0314f1017f350c17496830d6714597e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jonatan=20K=C5=82osko?= <jonatanklosko@gmail.com>
Date: Thu, 12 Feb 2026 18:45:41 +0100
Subject: [PATCH] Document environment variables behaviour

---
 lib/pythonx.ex | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/lib/pythonx.ex b/lib/pythonx.ex
index a2dc288..2db4ced 100644
--- a/lib/pythonx.ex
+++ b/lib/pythonx.ex
@@ -47,6 +47,13 @@ defmodule Pythonx do
 
   For more configuration options, refer to the [uv documentation](https://docs.astral.sh/uv/concepts/projects/dependencies/).
 
+  > #### Environment variables {: .info}
+  >
+  > Python `os.environ` is initialized using the OS process environment.
+  > Consequently, it does not account for env vars modified with
+  > `System.put_env/2` and similar. If you want to mirror certain env
+  > vars, you need to set them on `os.environ` using `Pythonx.eval/2`.
+
   ## Options
 
     * `:force` - if true, runs with empty project cache. Defaults to `false`.