Index: configure.ac
===================================================================
diff -u -rcd18d47f5e3a972323f00af2cb6a42c9dc9d1a54 -rfccf09e0f22cd91e00f937625d6510dcf35dbcd4
--- configure.ac	(.../configure.ac)	(revision cd18d47f5e3a972323f00af2cb6a42c9dc9d1a54)
+++ configure.ac	(.../configure.ac)	(revision fccf09e0f22cd91e00f937625d6510dcf35dbcd4)
@@ -57,7 +57,7 @@
 		[build nsf with memcount debug support (default: disabled)]),
         [enable_memcount=$enableval], [enable_memcount=no])
 AC_ARG_ENABLE([development],
-	AS_HELP_STRING([--enable-development],
+	AS_HELP_STRING([--enable-development=yes|test],
 		[build nsf with development support (intensive runtime checking, etc.; default: disabled)]),
         [enable_development=$enableval], [enable_development=no])
 AC_ARG_ENABLE([assertions],
@@ -197,6 +197,9 @@
 if test "$enable_development" = yes; then
    AC_DEFINE([NSF_DEVELOPMENT], [1], [Are we building with development support?])
 fi
+if test "$enable_development" = full; then
+   AC_DEFINE([NSF_DEVELOPMENT_TEST], [1], [Are we building with development support and intesive testing?])
+fi
 
 if test "$enable_memcount" = yes; then
    AC_DEFINE([NSF_MEM_COUNT], [1], [Are we building with memcount support?])
Index: generic/nsf.c
===================================================================
diff -u -r41e05440d57881136dac05fe1b02c5bd5897edea -rfccf09e0f22cd91e00f937625d6510dcf35dbcd4
--- generic/nsf.c	(.../nsf.c)	(revision 41e05440d57881136dac05fe1b02c5bd5897edea)
+++ generic/nsf.c	(.../nsf.c)	(revision fccf09e0f22cd91e00f937625d6510dcf35dbcd4)
@@ -5,7 +5,7 @@
  *      for supporting language-oriented programming.  For details, see
  *      http://next-scripting.org/.
  *
- * Copyright (C) 1999-2016 Gustaf Neumann (a) (b)
+ * Copyright (C) 1999-2017 Gustaf Neumann (a) (b)
  * Copyright (C) 1999-2007 Uwe Zdun (a) (b)
  * Copyright (C) 2007-2008 Martin Matuska (b)
  * Copyright (C) 2010-2016 Stefan Sobernig (b)
@@ -838,7 +838,7 @@
   /*fprintf(stderr, "ParseContextRelease %p status %.6x %d elements\n",
     pcPtr, status, pcPtr->objc);*/
 
-#if !defined(NDEBUG)
+#if defined(NSF_DEVELOPMENT_TEST)
   {
     /*
      * Perform a general consistency check: although the contents of the parse
@@ -2597,7 +2597,7 @@
  *
  *----------------------------------------------------------------------
  */
-#if !defined(NDEBUG)
+#if defined(NSF_DEVELOPMENT_TEST)
 static void ValidClassListTail(const char *what, NsfClasses *classListPtr) {
   NsfClasses *sl, *tail;
 
@@ -2810,16 +2810,16 @@
   return pl;
 }
 
-#if defined(NDEBUG)
-#define AssertOrderIsWhite(arg)
-#else
+#if defined(NSF_DEVELOPMENT_TEST)
 static void AssertOrderIsWhite(NsfClasses *order) {
   register NsfClasses *pc;
 
   for (pc = order; pc != NULL; pc = pc->nextPtr) {
     assert(pc->cl->color == WHITE);
   }
 }
+#else
+# define AssertOrderIsWhite(arg)
 #endif
 
 /*
@@ -5938,7 +5938,8 @@
 
 void
 Nsf_DeleteNamespace(Tcl_Interp *interp, Tcl_Namespace *nsPtr) {
-#if !defined(NDEBUG)
+
+#if defined(NSF_DEVELOPMENT_TEST)
   int activationCount = 0;
   Tcl_CallFrame *f = (Tcl_CallFrame *)Tcl_Interp_framePtr(interp);
 
@@ -6273,7 +6274,7 @@
   return cmd;
 }
 
-#if !defined(NDEBUG)
+#if defined(NSF_DEVELOPMENT_TEST)
 /*
  *----------------------------------------------------------------------
  * ReverseLookupCmdFromCmdTable --
@@ -6333,7 +6334,7 @@
  *----------------------------------------------------------------------
  */
 
-static NsfObject * GetHiddenObjectFromCmd(Tcl_Interp *interp, Tcl_Command cmdPtr) nonnull(1);
+static NsfObject *GetHiddenObjectFromCmd(Tcl_Interp *interp, Tcl_Command cmdPtr) nonnull(1);
 
 static NsfObject *
 GetHiddenObjectFromCmd(Tcl_Interp *interp, Tcl_Command cmdPtr) {
@@ -8361,7 +8362,7 @@
         continue;
       }
 
-#if !defined(NDEBUG)
+#if defined(NSF_DEVELOPMENT_TEST)
       {
         /*
          * Make sure, we can still lookup the object; the object has to be still
@@ -31440,7 +31441,7 @@
    * physical destroy round, we can set the counter to an appropriate
    * value to ensure deletion.
    */
-#if defined(NSF_DEVELOPMENT)
+#if defined(NSF_DEVELOPMENT_TEST)
   if (unlikely(object->refCount != 1)) {
     if (object->refCount > 1) {
       NsfLog(interp, NSF_LOG_WARN,  "RefCount for obj %p %d (name %s) > 1",
Index: generic/nsf.h
===================================================================
diff -u -rb8ca306282c9a1000b1c93ffd97f7f4673953f65 -rfccf09e0f22cd91e00f937625d6510dcf35dbcd4
--- generic/nsf.h	(.../nsf.h)	(revision b8ca306282c9a1000b1c93ffd97f7f4673953f65)
+++ generic/nsf.h	(.../nsf.h)	(revision fccf09e0f22cd91e00f937625d6510dcf35dbcd4)
@@ -191,6 +191,10 @@
 # define NSF_DTRACE_METHOD_RETURN_PROBE(cscPtr,retCode) {}
 #endif
 
+#if defined(NSF_DEVELOPMENT_FULL) && !defined(NSF_DEVELOPMENT)
+# define NSF_DEVELOPMENT 1
+#endif
+
 #ifdef NSF_DEVELOPMENT
 /*
  * The activation counts checking is best performed via the MEM_COUNT