Setup.thread.in was misnamed so it has been replaced by
Setup.config.in. The latter contains all configure-time selectable
modules; currently thread and gc.
diff --git a/Modules/Setup.config.in b/Modules/Setup.config.in
new file mode 100644
index 0000000..649567c
--- /dev/null
+++ b/Modules/Setup.config.in
@@ -0,0 +1,14 @@
+# This file is transmogrified into Setup.config by config.status.
+
+# The purpose of this file is to conditionally enable certain modules
+# based on configure-time options. Currently thread support and
+# garbage collection support are the only two modules so enabled.
+
+# *NOTE*: if the configure script decides it can't support threads,
+# the thread module will still be enabled and cause compile errors.
+# The solution is to use --without-threads on platforms that don't
+# support threads.
+@USE_THREAD_MODULE@thread threadmodule.c
+
+# Garbage collection enabled with --with-cycle-gc
+@USE_GC_MODULE@gc gcmodule.c