def test_custom_target_changes_cause_rebuild(self):
        '''
        Test that in a custom target, changes to the input files, the
        ExternalProgram, and any File objects on the command-line cause
        a rebuild.
        '''
        testdir = os.path.join(self.common_test_dir, '57 custom header generator')
        self.init(testdir)
        self.build()
        # Immediately rebuilding should not do anything
        self.assertBuildIsNoop()
        # Changing mtime of these should rebuild everything
        for f in ('input.def', 'makeheader.py', 'somefile.txt'):
            self.utime(os.path.join(testdir, f))
            self.assertBuildRelinkedOnlyTarget('prog')

        Test that in a custom target, changes to the input files, the
        ExternalProgram, and any File objects on the command-line cause
        a rebuild.
        
unittests/allplatformstests.py