Issue #15560: Fix building _sqlite3 extension on OS X with an SDK.
diff --git a/setup.py b/setup.py
index d419d48..bc1e1bb 100644
--- a/setup.py
+++ b/setup.py
@@ -1041,12 +1041,12 @@
         if host_platform == 'darwin':
             sysroot = macosx_sdk_root()
 
-        for d in inc_dirs + sqlite_inc_paths:
-            f = os.path.join(d, "sqlite3.h")
-
+        for d_ in inc_dirs + sqlite_inc_paths:
+            d = d_
             if host_platform == 'darwin' and is_macosx_sdk_path(d):
-                f = os.path.join(sysroot, d[1:], "sqlite3.h")
+                d = os.path.join(sysroot, d[1:])
 
+            f = os.path.join(d, "sqlite3.h")
             if os.path.exists(f):
                 if sqlite_setup_debug: print("sqlite: found %s"%f)
                 with open(f) as file: