From 3218757024bd6111151f522eb0f0898eb2880e55 Mon Sep 17 00:00:00 2001
From: Filippo Vicentini <filippovicentini@gmail.com>
Date: Tue, 18 Jan 2022 23:55:41 +0100
Subject: [PATCH] docs

---
 PyPreferences.jl/src/which.jl | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/PyPreferences.jl/src/which.jl b/PyPreferences.jl/src/which.jl
index 94539d3c..ff2a2b7a 100644
--- a/PyPreferences.jl/src/which.jl
+++ b/PyPreferences.jl/src/which.jl
@@ -1,3 +1,7 @@
+# This file vendors the utility `Sys.which` for Julia versions prior to 1.7,
+# as in 1.6 it called `realpath` and therefore breaks virtual environment
+# detection. (Without this, all `test/test_venv.jl` would fail).
+
 @static if VERSION >= v"1.7.0"
     const _which = Sys.which
 else