--- ceph-15.1.0/src/common/bit_str.h.orig	2020-02-03 09:47:20.047149798 -0500
+++ ceph-15.1.0/src/common/bit_str.h	2020-02-03 09:47:50.213149798 -0500
@@ -17,6 +17,7 @@
 #include <cstdint>
 #include <iosfwd>
 #include <functional>
+#include <ostream>
 
 namespace ceph {
   class Formatter;