bpo-42521: Add note about 'Python -d' only working on debug builds (GH-23607)
(cherry picked from commit 99b594404d364b363c184f48338d6ee81bee26dd)
Co-authored-by: Pablo Galindo <Pablogsal@gmail.com>
diff --git a/Python/initconfig.c b/Python/initconfig.c
index e882a1f..3caed38 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -42,7 +42,8 @@
and comparing bytes/bytearray with str. (-bb: issue errors)\n\
-B : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x\n\
-c cmd : program passed in as string (terminates option list)\n\
--d : debug output from parser; also PYTHONDEBUG=x\n\
+-d : turn on parser debugging output (for experts only, only works on\n\
+ debug builds); also PYTHONDEBUG=x\n\
-E : ignore PYTHON* environment variables (such as PYTHONPATH)\n\
-h : print this help message and exit (also --help)\n\
";