diff --git a/platformio/proc.py b/platformio/proc.py
index acfce4d9..707245a1 100644
--- a/platformio/proc.py
+++ b/platformio/proc.py
@@ -69,7 +69,7 @@ class BuildAsyncPipe(AsyncPipeBase):
         print_immediately = False
 
         for char in iter(lambda: self._pipe_reader.read(1), ""):
-            self._buffer += char
+            # self._buffer += char
 
             if line and char.strip() and line[-3:] == (char * 3):
                 print_immediately = True