This option redirects the diagnostics output by the
--xrefto options to a file.
the file to contain the redirected diagnostic output.
The specified file is created when diagnostics are output. If a file of the same name already exists, it is overwritten. However, if diagnostics are not output, a file is not created. In this case, the contents of any existing file with the same name remain unchanged.
specified without a path, it is created in the output directory,
that is, the directory where the output image is being written.