Issue #15560: Fix building _sqlite3 extension on OS X with an SDK.

Misc/NEWS

@@ -304,6 +304,8 @@ Tests
 Build
 -----
 
+- Issue #15560: Fix building _sqlite3 extension on OS X with an SDK.
+
 - Issue #8847: Disable COMDAT folding in Windows PGO builds.
 
 - Issue #14018: Fix OS X Tcl/Tk framework checking when using OS X SDKs.

setup.py

@@ -1041,12 +1041,12 @@ class PyBuildExt(build_ext):
         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: