diff -up gnupg-2.2.19/common/iobuf.c.build gnupg-2.2.19/common/iobuf.c
--- gnupg-2.2.19/common/iobuf.c.build	2019-07-09 11:08:45.000000000 +0200
+++ gnupg-2.2.19/common/iobuf.c	2020-01-29 19:10:03.488980061 +0100
@@ -118,6 +118,7 @@ struct close_cache_s
 typedef struct close_cache_s *close_cache_t;
 static close_cache_t close_cache;
 
+int iobuf_debug_mode;
 
 
 #ifdef HAVE_W32_SYSTEM
diff -up gnupg-2.2.19/common/iobuf.h.build gnupg-2.2.19/common/iobuf.h
--- gnupg-2.2.19/common/iobuf.h.build	2017-02-24 13:46:24.000000000 +0100
+++ gnupg-2.2.19/common/iobuf.h	2020-01-29 19:08:47.961340383 +0100
@@ -250,11 +250,7 @@ struct iobuf_struct
 };
 
 #ifndef EXTERN_UNLESS_MAIN_MODULE
-#if defined (__riscos__) && !defined (INCLUDED_BY_MAIN_MODULE)
 #define EXTERN_UNLESS_MAIN_MODULE extern
-#else
-#define EXTERN_UNLESS_MAIN_MODULE
-#endif
 #endif
 EXTERN_UNLESS_MAIN_MODULE int iobuf_debug_mode;
 
diff -up gnupg-2.2.19/g10/options.h.build gnupg-2.2.19/g10/options.h
--- gnupg-2.2.19/g10/options.h.build	2020-01-29 12:54:10.308621663 +0100
+++ gnupg-2.2.19/g10/options.h	2020-01-29 19:10:44.659238547 +0100
@@ -32,7 +32,7 @@
 
 #ifndef EXTERN_UNLESS_MAIN_MODULE
 /* Norcraft can't cope with common symbols */
-#if defined (__riscos__) && !defined (INCLUDED_BY_MAIN_MODULE)
+#if !defined (INCLUDED_BY_MAIN_MODULE)
 #define EXTERN_UNLESS_MAIN_MODULE extern
 #else
 #define EXTERN_UNLESS_MAIN_MODULE