$ok &= $run_program_fail->($program, '--clean-all file1 file2', 'more than one file');
$ok &= $run_program_fail->($program, '- file', 'hyphen cannot be used as color string');
$ok &= $run_program_fail->($program, '-', 'hyphen must be preceeded by color string');
$ok &= $run_program_fail->($program, '--clean-all file1 file2', 'more than one file');
$ok &= $run_program_fail->($program, '- file', 'hyphen cannot be used as color string');
$ok &= $run_program_fail->($program, '-', 'hyphen must be preceeded by color string');