diff --git a/lib/binutils.c b/lib/binutils.c
index 13f212b8..f05869e3 100644
--- a/lib/binutils.c
+++ b/lib/binutils.c
@@ -33,7 +33,10 @@ abs (int x)
 int
 chown (char const *file_name, uid_t owner, gid_t group)
 {
-  eputs ("chown stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("chown stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -41,9 +44,10 @@ chown (char const *file_name, uid_t owner, gid_t group)
 int
 ctime (int x)
 {
-#if NOISY_TIMES
-  eputs ("ctime stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("ctime stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -84,7 +88,10 @@ fgets (char *s, int count, FILE *stream)
 int
 frexp (int x)
 {
-  eputs ("frexp stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("frexp stub\n");
+  stub = 1;
   return 0;
 }
 
@@ -97,7 +104,10 @@ perror (char const *message)
 int
 sigsetmask (int x)
 {
-  eputs ("sigsetmask stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("sigsetmask stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -153,7 +163,10 @@ strspn (char const *string, char const *skipset)
 int
 sys_siglist (int x)
 {
-  eputs ("sys_siglist stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("sys_siglist stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -161,7 +174,10 @@ sys_siglist (int x)
 int
 umask (int x)
 {
-  eputs ("umask stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("umask stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -169,9 +185,9 @@ umask (int x)
 int
 utime (int x)
 {
-#if NOISY_TIMES
-  eputs ("utime stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("utime stub\n");
   errno = 0;
   return 0;
 }
@@ -180,7 +196,10 @@ utime (int x)
 int
 fscanf (FILE *stream, char const *template, ...)
 {
-  eputs ("fscan stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("fscan stub\n");
+  stub = 1;
   return 0;
 }
 
@@ -197,16 +216,20 @@ bsearch (void const *key, void const *array, size_t count, size_t size, void (*c
 bsearch (void const *key, void const *array, size_t count, size_t size, comparison_fn_t compare)
 #endif
 {
-  eputs ("bsearch stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("bsearch stub\n");
+  stub = 1;
   return 0;
 }
 
 struct tm *
 gmtime (time_t const *time)
 {
-#if NOISY_TIMES
-  eputs ("gmtime stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("gmtime stub\n");
+  stub = 1;
   errno = 0;
   return localtime (time);
 }
@@ -245,8 +268,11 @@ size_t
 strftime (char *s, size_t size, char const *template,
           struct tm const *brokentime)
 {
-   eputs ("strftime stub\n");
-   return template;
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("strftime stub\n");
+  stub = 1;
+  return template;
 }
 
 #if !__MESC__
@@ -256,7 +282,10 @@ size_t
 mbstowcs (wchar_t *wstring, char const *string,
           size_t size)
 {
-  eputs ("mbstowcs stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("mbstowcs stub\n");
+  stub = 1;
   strcpy (wstring, string);
   return strlen (string);
 }
diff --git a/lib/gcc.c b/lib/gcc.c
index c8eeb9e6..ef0ac469 100644
--- a/lib/gcc.c
+++ b/lib/gcc.c
@@ -34,9 +34,10 @@ freopen (char const *file_name, char const *opentype, FILE *stream)
 clock_t
 times (struct tms *buffer)
 {
-#if NOISY_TIMES
-  eputs ("times stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("times stub\n");
+  stub = 1;
   return 0;
 }
 
@@ -54,14 +55,20 @@ sleep (unsigned int seconds)
 double
 __divdi3 (double a, double b)
 {
-  eputs ("__divdi3 stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__divdi3 stub\n");
+  stub = 1;
   return ((int)a / (int)b);
 }
 
 double
 __moddi3 (double a, double b)
 {
-  eputs ("__moddi3 stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__moddi3 stub\n");
+  stub = 1;
   return ((int) a %(int)b);
 }
 
@@ -112,7 +119,10 @@ alarm (unsigned int seconds)
 struct passwd *
 getpwnam (const char *NAME)
 {
-  eputs ("getpwnam stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("getpwnam stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
diff --git a/lib/glibc.c b/lib/glibc.c
index 37ed69e7..08b830cb 100644
--- a/lib/glibc.c
+++ b/lib/glibc.c
@@ -21,7 +21,10 @@
 int
 __cleanup ()
 {
-  eputs ("__cleanup stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__cleanup stub\n");
+  stub = 1;
   return 0;
 }
 
diff --git a/lib/libc+tcc-gcc.c b/lib/libc+tcc-gcc.c
index 3448a68b..02f1f2ff 100644
--- a/lib/libc+tcc-gcc.c
+++ b/lib/libc+tcc-gcc.c
@@ -112,44 +112,49 @@ __ashrdi3 (long long a, int b)
 long double
 __floatundixf (unsigned long long a)
 {
-#if NOISY_FLOATS
-  eputs ("__floatundix stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__floatundix stub\n");
+  stub = 1;
   return 0;
 }
 
 unsigned long long
 __fixunsxfdi (double a1)
 {
-#if NOISY_FLOATS
-  eputs ("__fixunsxfdi stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__fixunsxfdi stub\n");
+  stub = 1;
   return 0;
 }
 
 unsigned long long
 __fixdfdi (double a1)
 {
-#if NOISY_FLOATS
-  eputs ("__fixdfdi stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__fixdfdi stub\n");
+  stub = 1;
   return 0;
 }
 
 unsigned long long
 __fixxfdi (double a1)
 {
-#if NOISY_FLOATS
-  eputs ("__fixxfdi stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__fixxfdi stub\n");
+  stub = 1;
   return 0;
 }
 
 unsigned long long
 __fixsfdi (double a1)
 {
-#if NOISY_FLOATS
-  eputs ("__fixsfdi stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__fixsfdi stub\n");
+  stub = 1;
   return 0;
 }
diff --git a/lib/libc+tcc.c b/lib/libc+tcc.c
index 3e41df30..064c2cc4 100644
--- a/lib/libc+tcc.c
+++ b/lib/libc+tcc.c
@@ -64,7 +64,7 @@ search_path (char const *file_name)
 {
   static char buf[256];
   char *path = getenv ("PATH");
-  if (getenv ("MESC_DEBUG"))
+  if (__mes_debug ())
     {
       eputs ("\n search-path: "); eputs (file_name); eputs ("\n");
     }
@@ -75,7 +75,7 @@ search_path (char const *file_name)
         end = strchr (path, '\0');
       strncpy (buf, path, end - path);
       buf[end - path] = 0;
-      if (getenv ("MESC_DEBUG"))
+      if (__mes_debug ())
         {
           eputs (" dir: "); eputs (buf); eputs ("\n");
         }
@@ -84,7 +84,7 @@ search_path (char const *file_name)
       strcat (buf, file_name);
       if (!access (buf, X_OK))
         {
-          if (getenv ("MESC_DEBUG"))
+          if (__mes_debug ())
             {
               eputs (" found: "); eputs (buf); eputs ("\n");
             }
@@ -105,7 +105,7 @@ execvp (char const *file_name, char *const argv[])
       errno = ENOENT;
       return -1;
     }
-  if (getenv ("MESC_DEBUG"))
+  if (__mes_debug ())
     {
       eputs (" EXEC: "); eputs (file_name); eputs ("\n");
       int i = 0;
@@ -170,7 +170,7 @@ fread (void *data, size_t size, size_t count, FILE *stream)
 size_t
 fwrite (void const *data, size_t size, size_t count, FILE *stream)
 {
-  if (getenv ("MESC_DEBUG"))
+  if (__mes_debug ())
     {
       eputs ("fwrite "); eputs (itoa ((int)stream));
       eputs ("  "); eputs (itoa (size)); eputs ("\n");
@@ -180,7 +180,7 @@ fwrite (void const *data, size_t size, size_t count, FILE *stream)
     return 0;
   int bytes = write ((int)stream, data, size * count);
 
-  if (getenv ("MESC_DEBUG"))
+  if (__mes_debug ())
     {
       eputs (" => "); eputs (itoa (bytes)); eputs ("\n");
     }
@@ -199,7 +199,7 @@ ftell (FILE *stream)
 FILE*
 fopen (char const *file_name, char const *opentype)
 {
-  if (getenv ("MESC_DEBUG"))
+  if (__mes_debug ())
     {
       eputs ("fopen "); eputs (file_name);
       eputs (" "); eputs (opentype); eputs ("\n");
@@ -224,7 +224,7 @@ fopen (char const *file_name, char const *opentype)
   else
     fd = open (file_name, 0, 0);
 
-  if (getenv ("MESC_DEBUG"))
+  if (__mes_debug ())
     {
       eputs (" => fd="); eputs (itoa (fd)); eputs ("\n");
     }
@@ -244,9 +244,10 @@ fseek (FILE *stream, long offset, int whence)
 int
 gettimeofday (struct timeval *tv, struct timezone *tz)
 {
-#if NOISY_TIMES
-  eputs ("gettimeofday stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("gettimeofday stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -254,16 +255,20 @@ gettimeofday (struct timeval *tv, struct timezone *tz)
 double
 ldexp (double x, int exp)
 {
-  eputs ("ldexp stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("ldexp stub\n");
+  stub = 1;
   return 0;
 }
 
 struct tm *
 localtime (time_t const *timep)
 {
-#if NOISY_TIMES
-  eputs ("localtime stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("localtime stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -485,9 +490,10 @@ strstr (char const *haystack, char const *needle)
 double
 strtod (char const *string, char **tailptr)
 {
-#if NOISY_FLOATS
-  eputs ("strtod stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("strtod stub\n");
+  stub = 1;
   return 0;
 }
 
@@ -520,8 +526,6 @@ strtol (char const *string, char **tailptr, int base)
   return abtoi (p, base);
 }
 
-#if 1
-
 long long int
 strtoll (char const *string, char **tailptr, int base)
 {
@@ -540,39 +544,13 @@ strtoull (char const *string, char **tailptr, int base)
   return strtol (string, tailptr, base);
 }
 
-#else
-
-long long int
-strtoll (char const *string, char **tailptr, int base)
-{
-  eputs ("strtoll stub\n");
-  return 0;
-}
-
-unsigned long
-strtoul (char const *string, char **tailptr, int base)
-{
-  eputs ("strtoul stub\n");
-  return 0;
-}
-
-unsigned long long
-strtoull (char const *string, char **tailptr, int base)
-{
-  // *endptr = p;
-  // return abtoi (endptr, base);
-  eputs ("strtoull stub\n");
-  return 0;
-}
-
-#endif
-
 time_t
 time (time_t *tloc)
 {
-#if NOISY_TIMES
-  eputs ("time stub\n");
-#endif
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("time stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
diff --git a/lib/libc.c b/lib/libc.c
index 62c31ad3..99b28e30 100644
--- a/lib/libc.c
+++ b/lib/libc.c
@@ -49,6 +49,20 @@ int g_stdin = 0;
 
 void _env ();
 
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
+int
+__mes_debug ()
+{
+  static int __mes_debug = -1;
+  if (__mes_debug == -1)
+    {
+      char *p = getenv ("MES_DEBUG");
+      __mes_debug = p ? MAX (itoa (p), 1) : 0;
+    }
+  return __mes_debug;
+}
+
 int
 getchar ()
 {
diff --git a/lib/libg.c b/lib/libg.c
index bf511f03..b892ca06 100644
--- a/lib/libg.c
+++ b/lib/libg.c
@@ -45,27 +45,39 @@
 int
 __cleanup ()
 {
-  eputs ("__cleanup stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__cleanup stub\n");
+  stub = 1;
   return 0;
 }
 
 int
 __libc_subinit ()
 {
-  eputs ("__libc_subinit stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__libc_subinit stub\n");
+  stub = 1;
   return 0;
 }
 
 int
 __syscall_error ()
 {
-  eputs ("__syscall_error stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__syscall_error stub\n");
+  stub = 1;
   return 0;
 }
 
 int
 __fpu_control ()
 {
-  eputs ("__fpu_control stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("__fpu_control stub\n");
+  stub = 1;
   return 0;
 }
diff --git a/lib/m4.c b/lib/m4.c
index 1c9bcfb9..8ffcb152 100644
--- a/lib/m4.c
+++ b/lib/m4.c
@@ -21,14 +21,20 @@
 int
 abort ()
 {
-  eputs ("abort stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("abort stub\n");
+  stub = 1;
   return 0;
 }
 
 int
 atof (int x)
 {
-  eputs ("atof stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("atof stub\n");
+  stub = 1;
   return 0;
 }
 
@@ -65,7 +71,10 @@ fileno (FILE *stream)
 int
 fpurge (FILE *stream)
 {
-  eputs ("fpurge stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("fpurge stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -73,7 +82,10 @@ fpurge (FILE *stream)
 size_t
 freadahead (FILE *fp)
 {
-  eputs ("freadahead stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("freadahead stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -131,7 +143,10 @@ mktemp (char *template)
 int
 pclose (int x)
 {
-  eputs ("pclose stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("pclose stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -139,7 +154,10 @@ pclose (int x)
 int
 popen (int x)
 {
-  eputs ("popen stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("popen stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -153,7 +171,10 @@ rindex (char const *s, int c)
 int
 rewind (int x)
 {
-  eputs ("rewind stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("rewind stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -161,7 +182,10 @@ rewind (int x)
 int
 setbuf (int x)
 {
-  eputs ("setbuf stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("setbuf stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
@@ -169,12 +193,14 @@ setbuf (int x)
 int
 system (int x)
 {
-  eputs ("system stub\n");
+  static int stub = 0;
+  if (__mes_debug () && !stub)
+    eputs ("system stub\n");
+  stub = 1;
   errno = 0;
   return 0;
 }
 
-//char const *const sys_errlist[40] = {
 char *sys_errlist[] = {
   "error 00",
   "error 01",
@@ -223,7 +249,10 @@ int sys_nerr = 39;
 char *
 strerror (int errnum)
 {
-  eputs ("strerror errnum="); eputs (itoa (errnum)); eputs ("\n");
+  if (__mes_debug ())
+    {
+      eputs ("strerror errnum="); eputs (itoa (errnum)); eputs ("\n");
+    }
   if (errnum > 0 && errnum <= sys_nerr)
     return sys_errlist[errnum];
   return "sterror: unknown error";