Explicitly flushed bjam's standard output after printing out '...patience...' lines. Without a fflush() call these lines may get buffered and displayed all at once only after the first actual target has been built. It seems that Visual C++ compiler's runtime does not use line buffering for its standard output stream if given a pipe as its standard output (encountered with bjam compiled using msvc 10 and run by piping its output through the Cygwin tee utility).

[SVN r78545]

v2/engine/headers.c

@@ -137,7 +137,10 @@ headers1(
     static int count = 0;
     ++count;
     if ( ((count == 100) || !( count % 1000 )) && DEBUG_MAKE )
+    {
         printf("...patience...\n");
+        fflush(stdout);
+    }
 #endif
 
     /* the following regexp is used to detect cases where a  */

v2/engine/make.c

@@ -714,7 +714,10 @@ void make0
         ++counts->targets;
 #else
         if ( !( ++counts->targets % 1000 ) && DEBUG_MAKE )
+        {
             printf( "...patience...\n" );
+            fflush(stdout);
+        }
 #endif
 
         if ( fate == T_FATE_ISTMP )