diff --git a/compiler/base/hierarchy_design.py b/compiler/base/hierarchy_design.py
index 1321f06a..b0370179 100644
--- a/compiler/base/hierarchy_design.py
+++ b/compiler/base/hierarchy_design.py
@@ -7,7 +7,6 @@
 #
 import hierarchy_layout
 import hierarchy_spice
-import verify
 import debug
 import os
 from globals import OPTS
@@ -55,6 +54,7 @@ class hierarchy_design(hierarchy_spice.spice, hierarchy_layout.layout):
         
     def DRC_LVS(self, final_verification=False, force_check=False):
         """Checks both DRC and LVS for a module"""
+        import verify
 
         # No layout to check
         if OPTS.netlist_only:
@@ -94,6 +94,8 @@ class hierarchy_design(hierarchy_spice.spice, hierarchy_layout.layout):
 
     def DRC(self, final_verification=False):
         """Checks DRC for a module"""
+        import verify
+
         # Unit tests will check themselves.
         # Do not run if disabled in options.
 
@@ -117,6 +119,8 @@ class hierarchy_design(hierarchy_spice.spice, hierarchy_layout.layout):
 
     def LVS(self, final_verification=False):
         """Checks LVS for a module"""
+        import verify
+
         # Unit tests will check themselves.
         # Do not run if disabled in options.
 
diff --git a/compiler/characterizer/lib.py b/compiler/characterizer/lib.py
index b0df4394..92882db7 100644
--- a/compiler/characterizer/lib.py
+++ b/compiler/characterizer/lib.py
@@ -657,8 +657,12 @@ class lib:
                         ))
 
         # information of checks
-        (drc_errors, lvs_errors) = self.sram.DRC_LVS(final_verification=True)
-        datasheet.write("{0},{1},".format(drc_errors, lvs_errors))
+        # run it only the first time
+        try:
+            datasheet.write("{0},{1},".format(self.drc_errors, self.lvs_errors))
+        except AttributeError:
+            (self.drc_errors, self.lvs_errors) = self.sram.DRC_LVS(final_verification=True)
+            datasheet.write("{0},{1},".format(self.drc_errors, self.lvs_errors))            
         
         # write area
         datasheet.write(str(self.sram.width * self.sram.height) + ',')
diff --git a/compiler/debug.py b/compiler/debug.py
index a902bca0..f07471cc 100644
--- a/compiler/debug.py
+++ b/compiler/debug.py
@@ -40,7 +40,7 @@ def error(str, return_value=0):
     log("ERROR: file {0}: line {1}: {2}\n".format(
         os.path.basename(filename), line_number, str))
 
-    if globals.OPTS.debug_level > 0:
+    if globals.OPTS.debug_level > 0 and return_value != 0:
         import pdb
         pdb.set_trace()
     assert return_value == 0
diff --git a/compiler/verify/calibre.py b/compiler/verify/calibre.py
index 0a975599..443c91ca 100644
--- a/compiler/verify/calibre.py
+++ b/compiler/verify/calibre.py
@@ -219,16 +219,14 @@ def run_drc(cell_name, gds_name, extract=False, final_verification=False):
     errors = int(re.split(r'\W+', results[2])[5])
 
     # always display this summary
-    if errors > 0:
-        debug.error("{0}\tGeometries: {1}\tChecks: {2}\tErrors: {3}".format(cell_name,
+    result_str = "{0}\tGeometries: {1}\tChecks: {2}\tErrors: {3}".format(cell_name,
                                                                             geometries,
                                                                             rulechecks,
-                                                                            errors))
+                                                                            errors)
+    if errors > 0:
+        debug.warning(result_str)
     else:
-        debug.info(1, "{0}\tGeometries: {1}\tChecks: {2}\tErrors: {3}".format(cell_name,
-                                                                              geometries,
-                                                                              rulechecks,
-                                                                              errors))
+        debug.info(1, result_str)
     return errors
 
 
@@ -307,16 +305,15 @@ def run_lvs(cell_name, gds_name, sp_name, final_verification=False):
     out_errors = len(stdouterrors)
     total_errors = summary_errors + out_errors + ext_errors
 
-    if total_errors > 0:
-        debug.error("{0}\tSummary: {1}\tOutput: {2}\tExtraction: {3}".format(cell_name,
+    # always display this summary
+    result_str = "{0}\tSummary: {1}\tOutput: {2}\tExtraction: {3}".format(cell_name,
                                                                             summary_errors,
                                                                             out_errors,
-                                                                            ext_errors))
+                                                                            ext_errors)
+    if total_errors > 0:
+        debug.warning(result_str)
     else:
-        debug.info(1, "{0}\tSummary: {1}\tOutput: {2}\tExtraction: {3}".format(cell_name,
-                                                                              summary_errors,
-                                                                              out_errors,
-                                                                              ext_errors))
+        debug.info(1, result_str)
 
     return total_errors
 
diff --git a/compiler/verify/magic.py b/compiler/verify/magic.py
index e20c0499..5df6e698 100644
--- a/compiler/verify/magic.py
+++ b/compiler/verify/magic.py
@@ -200,13 +200,14 @@ def run_drc(cell_name, gds_name, extract=True, final_verification=False):
 
 
     # always display this summary
+    result_str = "DRC Errors {0}\t{1}".format(cell_name, errors)
     if errors > 0:
         for line in results:
             if "error tiles" in line:
                 debug.info(1,line.rstrip("\n"))
-        debug.error("DRC Errors {0}\t{1}".format(cell_name, errors))
+        debug.warning(result_str)
     else:
-        debug.info(1, "DRC Errors {0}\t{1}".format(cell_name, errors))
+        debug.info(1, result_str)
 
     return errors