diff --git a/tools/oneclick/base/hdl_config.py b/tools/oneclick/base/hdl_config.py
index 7ca1ccf0645cf6f2fbd6a185f5006d355cc9e920..c9e3063e3e173fa84ffb5602bd3c64f850911a94 100644
--- a/tools/oneclick/base/hdl_config.py
+++ b/tools/oneclick/base/hdl_config.py
@@ -122,6 +122,7 @@ class HdlConfig:
            - 'hdl_lib_excludes' defines the libraries that must be excluded for synthesis
         """
         # Get use_libs
+        use_libs = []
         if 'hdl_lib_uses_synth' in lib_dict:
             use_libs = lib_dict['hdl_lib_uses_synth'].split()
         if build_type=='sim':
@@ -160,13 +161,10 @@ class HdlConfig:
             lib_dict = self.libs.dicts[self.lib_names.index(lib_name)]
             # use recursion to include all used libs
             use_libs, exclude_libs = self.get_used_libs(build_type, lib_dict, exclude_libs)
-            try:
-                for use_lib in use_libs:
-                    if use_lib in self.lib_names:
-                        all_use_libs.append(use_lib)
-                        all_use_libs += self.derive_all_use_libs(build_type, use_lib, exclude_libs)
-            except NameError:
-                pass
+            for use_lib in use_libs:
+                if use_lib in self.lib_names:
+                    all_use_libs.append(use_lib)
+                    all_use_libs += self.derive_all_use_libs(build_type, use_lib, exclude_libs)
             # remove all duplicates from the list
             return cm.unique(all_use_libs)
         else:
@@ -186,14 +184,11 @@ class HdlConfig:
         for lib_dict in cm.listify(lib_dicts):
             lib_name = lib_dict['hdl_lib_name']
             use_libs, exclude_libs = self.get_used_libs(build_type, lib_dict, [])
-            try:
-                for use_lib in use_libs:
-                    if use_lib in lib_names:
-                        if lib_order.index(use_lib) > lib_order.index(lib_name):
-                            lib_order.remove(use_lib)
-                            lib_order.insert(lib_order.index(lib_name), use_lib)  # move used lib to just before this lib
-            except NameError:
-                pass
+            for use_lib in use_libs:
+                if use_lib in lib_names:
+                    if lib_order.index(use_lib) > lib_order.index(lib_name):
+                        lib_order.remove(use_lib)
+                        lib_order.insert(lib_order.index(lib_name), use_lib)  # move used lib to just before this lib
         # use recursion to keep on reordering the lib_order until it is stable
         if lib_names != lib_order:
             lib_order = self.derive_lib_order(build_type, lib_order)