Index: src/main.c
==================================================================
--- src/main.c
+++ src/main.c
@@ -53,10 +53,23 @@
 ** zero if and only if SQLite was compiled with mutexing code omitted due to
 ** the SQLITE_THREADSAFE compile-time option being set to 0.
 */
 int sqlite3_threadsafe(void){ return SQLITE_THREADSAFE; }
 
+/*
+** When compiling the test fixture or with debugging enabled (on Win32),
+** this variable being set to non-zero will cause OSTRACE macros to emit
+** extra diagnostic information.
+*/
+#if (defined(SQLITE_DEBUG) && SQLITE_OS_WIN) || \
+    (defined(SQLITE_TEST) || defined(SQLITE_FORCE_OS_TRACE))
+# ifndef SQLITE_DEBUG_OS_TRACE
+#   define SQLITE_DEBUG_OS_TRACE 0
+# endif
+  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
+#endif
+
 #if !defined(SQLITE_OMIT_TRACE) && defined(SQLITE_ENABLE_IOTRACE)
 /*
 ** If the following function pointer is not NULL and if
 ** SQLITE_ENABLE_IOTRACE is enabled, then messages describing
 ** I/O active are written using this function.  These messages

Index: src/os_common.h
==================================================================
--- src/os_common.h
+++ src/os_common.h
@@ -27,16 +27,16 @@
 */
 #ifdef MEMORY_DEBUG
 # error "The MEMORY_DEBUG macro is obsolete.  Use SQLITE_DEBUG instead."
 #endif
 
+/*
+** Declarations used for tracing the operating system interfaces.
+*/
 #if (defined(SQLITE_DEBUG) && SQLITE_OS_WIN) || \
     (defined(SQLITE_TEST) || defined(SQLITE_FORCE_OS_TRACE))
-# ifndef SQLITE_DEBUG_OS_TRACE
-#   define SQLITE_DEBUG_OS_TRACE 0
-# endif
-  int sqlite3OSTrace = SQLITE_DEBUG_OS_TRACE;
+  extern int sqlite3OSTrace;
 # define OSTRACE(X)          if( sqlite3OSTrace ) sqlite3DebugPrintf X
 #else
 # define OSTRACE(X)
 #endif