diff -rupN --no-dereference Python-3.10.0rc1/setup.py Python-3.10.0rc1-new/setup.py
--- Python-3.10.0rc1/setup.py	2021-08-04 16:36:56.256389156 +0200
+++ Python-3.10.0rc1-new/setup.py	2021-08-04 16:36:58.528366207 +0200
@@ -556,6 +556,8 @@ class PyBuildExt(build_ext):
             print("Failed to build these modules:")
             print_three_column(failed)
             print()
+            with open('mods_failed.txt', 'w') as fh:
+                fh.write(", ".join(failed) + "\n")
 
         if self.failed_on_import:
             failed = self.failed_on_import[:]