old_contents: import BaseEnvironment
  import os
  
  class Environment(BaseEnvironment.Environment):
     def __init__(self, **kw):
        apply(BaseEnvironment.Environment.__init__, (self,), kw)
  
        self.ConfigureCompiler()
  
     def ConfigureCompiler(self):
        cxx = os.path.basename(self['CXX'])
  
        if cxx.startswith("clang") or cxx.startswith("g++"):
           self.AppendUnique(CXXFLAGS=['-Wall', '-pedantic', '-g'])
  
new_contents: import BaseEnvironment
  import os
  
  class Environment(BaseEnvironment.Environment):
     def __init__(self, **kw):
        apply(BaseEnvironment.Environment.__init__, (self,), kw)
  
        self.ConfigureCompiler()
  
     def ConfigureCompiler(self):
        cxx = os.path.basename(self['CXX'])
  
        if cxx.startswith("clang") or cxx.startswith("g++"):
           self.AppendUnique(CXXFLAGS=['-Wall', '-Wextra', '-Wpedantic', '-g'])
  
subject: Enable extra compiler warnings.