--- a/build/qt4.py	2020-05-15 23:26:10.000000000 +0200
+++ a/build/qt4.py	2021-03-17 11:13:58.867445884 +0100
@@ -42,7 +42,7 @@ 
 import SCons.Tool
 import SCons.Util
 
-class ToolQt4Warning(SCons.Warnings.Warning):
+class ToolQt4Warning(SCons.Warnings.SConsWarning):
     pass
 
 class GeneratedMocFileNotIncluded(ToolQt4Warning):
--- a/build/qt5.py	2020-05-15 23:26:10.000000000 +0200
+++ a/build/qt5.py	2021-03-17 11:12:39.568689777 +0100
@@ -43,7 +43,7 @@ 
 import SCons.Tool
 import SCons.Util
 
-class ToolQt5Warning(SCons.Warnings.Warning):
+class ToolQt5Warning(SCons.Warnings.SConsWarning):
     pass
 
 class GeneratedMocFileNotIncluded(ToolQt5Warning):