From 54c7c23fbb5476dd7b031ac65a2e9a2082097998 Mon Sep 17 00:00:00 2001
From: Nguyen Huy Hoang <24520554@gm.uit.edu.vn>
Date: Thu, 26 Mar 2026 21:55:42 +0700
Subject: [PATCH] refactor: scope `build_src_flags` to project source
 compilation only

Signed-off-by: Nguyen Huy Hoang <181364121+huyhoang171106@users.noreply.github.com>
---
 platformio/builder/tools/piobuild.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/platformio/builder/tools/piobuild.py b/platformio/builder/tools/piobuild.py
index 8ef2522cf7..99ebd0d092 100644
--- a/platformio/builder/tools/piobuild.py
+++ b/platformio/builder/tools/piobuild.py
@@ -176,7 +176,9 @@ def ProcessProjectDeps(env):
             env.Exit(1)
 
     if "test" not in env["BUILD_TYPE"] or env.GetProjectOption("test_build_src"):
-        plb.env.BuildSources(
+        src_env = plb.env.Clone()
+        src_env.ProcessFlags(src_env.get("BUILD_SRC_FLAGS"))
+        src_env.BuildSources(
             "$BUILD_SRC_DIR", "$PROJECT_SRC_DIR", env.get("SRC_FILTER")
         )