From da9cec66d30c729f28b540916fbbc493eceeb0d1 Mon Sep 17 00:00:00 2001
From: ferdymercury <ferdymercury@users.noreply.github.com>
Date: Wed, 14 Oct 2026 10:57:36 +0200
Subject: [PATCH] [cling] treat empty SDKROOT as unset

Fixes https://github.com/root-project/root/issues/23712

Full credit goes to cxwx
---
 interpreter/cling/lib/Interpreter/CIFactory.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/interpreter/cling/lib/Interpreter/CIFactory.cpp b/interpreter/cling/lib/Interpreter/CIFactory.cpp
index 03ad72cb3a4bc..fecd1c746df42 100644
--- a/interpreter/cling/lib/Interpreter/CIFactory.cpp
+++ b/interpreter/cling/lib/Interpreter/CIFactory.cpp
@@ -380,7 +380,8 @@ namespace {
     if(arvIt != args.end() && ++arvIt != args.end())
       cling_osx_sysroot_directory = *arvIt;
     if (!llvm::sys::fs::exists(cling_osx_sysroot_directory)) {
-      if (!::getenv("SDKROOT")) {
+      auto env = std::getenv("SDKROOT");
+      if (!env || !*env) {
         std::array<char, 128> buffer;
         const auto xcrun_cmd = "xcrun  --show-sdk-path";
         std::unique_ptr<FILE, decltype(&pclose)> pipe(