#NEWLINE# def test_pkg_install_remove_are_mutex( self , capsys ) : #NEWLINE# #INDENT# with pytest . raises ( SystemExit ) : #NEWLINE# #INDENT# self . parser . parse_args ( 'pkg --install pkg2 --remove pkg1 host1' . split ( ) ) #NEWLINE# #UNINDENT# ( out , err ) = capsys . readouterr ( ) #NEWLINE# assert ( 'argument --remove: not allowed with argument --install' in err )