From a9e592650d6432d71b73cefe046e5fb818bb1ee1 Mon Sep 17 00:00:00 2001
From: Ed Morley <501702+edmorley@users.noreply.github.com>
Date: Thu, 7 May 2026 16:00:16 +0100
Subject: [PATCH] Reject the `POETRY_VIRTUALENVS_IN_PROJECT` env var too

Since it's another Poetry related env var that shouldn't be set
by the end user since it can break builds.

See:
https://python-poetry.org/docs/configuration/#virtualenvsin-project

GUS-W-22400354.
---
 CHANGELOG.md  | 1 +
 src/checks.rs | 1 +
 2 files changed, 2 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c23dd9b..5b8f850 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Updated pip from 26.0.1 to 26.1.1. ([#563](https://github.com/heroku/buildpacks-python/pull/563))
 - Updated Poetry from 2.3.4 to 2.4.0. ([#564](https://github.com/heroku/buildpacks-python/pull/564))
 - Updated uv from 0.11.6 to 0.11.11. ([#562](https://github.com/heroku/buildpacks-python/pull/562))
+- The forbidden env vars check now also rejects `POETRY_VIRTUALENVS_IN_PROJECT`. ([#566](https://github.com/heroku/buildpacks-python/pull/566))
 
 ## [6.4.1] - 2026-04-13
 
diff --git a/src/checks.rs b/src/checks.rs
index be4596f..1bba2a2 100644
--- a/src/checks.rs
+++ b/src/checks.rs
@@ -20,6 +20,7 @@ const FORBIDDEN_ENV_VARS: &[&str] = &[
     "POETRY_DATA_DIR",
     "POETRY_HOME",
     "POETRY_VIRTUALENVS_CREATE",
+    "POETRY_VIRTUALENVS_IN_PROJECT",
     "POETRY_VIRTUALENVS_USE_POETRY_PYTHON",
     "PYTHONHOME",
     "PYTHONINSPECT",