diff --git a/src/simulator/wscript b/src/simulator/wscript
index 3f038d813..fec0412c0 100644
--- a/src/simulator/wscript
+++ b/src/simulator/wscript
@@ -7,7 +7,9 @@ import Params
 def set_options(opt):
     opt.add_option('--high-precision-as-double',
                    help=('Whether to use a double floating point'
-                         ' type for high precision time values'),
+                         ' type for high precision time values'
+                         ' WARNING: this option only has effect '
+                         'with the configure command.'),
                    action="store_true", default=False,
                    dest='high_precision_as_double')
 
diff --git a/wscript b/wscript
index d67039a54..b5be10dda 100644
--- a/wscript
+++ b/wscript
@@ -7,6 +7,7 @@ import shutil
 import Params
 import Object
 import pproc as subprocess
+import optparse
 
 Params.g_autoconfig = 1
 
@@ -23,11 +24,32 @@ def dist_hook(srcdir, blddir):
     shutil.rmtree("doc/latex")
 
 def set_options(opt):
+
+    def debug_option_callback(option, opt, value, parser):
+        if value == 'debug':
+            setattr(parser.values, option.dest, 'ultradebug')
+        elif value == 'optimized':
+            setattr(parser.values, option.dest, 'optimized')
+        else:
+            raise optparse.OptionValueError("allowed --debug-level values"
+                                            " are debug, optimized.")
+
+    opt.add_option('-d', '--debug-level',
+                   action='callback',
+                   type=str, dest='debug_level', default='debug',
+                   help=('Specify the debug level, does nothing if CFLAGS is set'
+                         ' in the environment. [Allowed Values: debug, optimized].'
+                         ' WARNING: this option only has effect '
+                         'with the configure command.'),
+                   callback=debug_option_callback)
+    
     # options provided by the modules
     opt.tool_options('compiler_cxx')
 
     opt.add_option('--enable-gcov',
-                   help=('Enable code coverage analysis'),
+                   help=('Enable code coverage analysis.'
+                         ' WARNING: this option only has effect '
+                         'with the configure command.'),
                    action="store_true", default=False,
                    dest='enable_gcov')
 
@@ -59,10 +81,13 @@ def configure(conf):
     if not conf.check_tool('compiler_cxx'):
         Params.fatal("No suitable compiler found")
 
-
     # create the second environment, set the variant and set its name
     variant_env = conf.env.copy()
-    variant_name = Params.g_options.debug_level.lower()
+    debug_level = Params.g_options.debug_level.lower()
+    if debug_level == 'ultradebug':
+        variant_name = 'debug'
+    else:
+        variant_name = debug_level
 
     if Params.g_options.enable_gcov:
         variant_name += '-gcov'
@@ -79,13 +104,17 @@ def configure(conf):
     conf.setenv(variant_name)
 
     variant_env.append_value('CXXDEFINES', 'RUN_SELF_TESTS')
-    variant_env.append_value('CXXFLAGS', ['-Wall', '-Werror'])
+    
+    if os.path.basename(conf.env['CXX']).startswith("g++"):
+        variant_env.append_value('CXXFLAGS', ['-Wall', '-Werror'])
+
     if 'debug' in Params.g_options.debug_level.lower():
         variant_env.append_value('CXXDEFINES', 'NS3_DEBUG_ENABLE')
         variant_env.append_value('CXXDEFINES', 'NS3_ASSERT_ENABLE')
 
     if sys.platform == 'win32':
-        variant_env.append_value("LINKFLAGS", "-Wl,--enable-runtime-pseudo-reloc")
+        if os.path.basename(conf.env['CXX']).startswith("g++"):
+            variant_env.append_value("LINKFLAGS", "-Wl,--enable-runtime-pseudo-reloc")
 
     conf.sub_config('src')