Comment 2 for bug 2057780

Thanks for the report. That's a very large file indeed.

Could you check if there is anything else in the error log at the time when it fails?

    print(exception.error_log)

should give you the current list of logged errors. It might be that lxml misguesses the reason for the error and somehow reports a non-fatal memory related error (however that might happen) instead of an actual parsing failure.

It might also be that you are hitting some other resource limit in libxml2. Have you tried stream-parsing the document with libxml2's xmllint tool?