error Object 203 0 not defined when using stub_to_print

[g-raffy]

Object 203 0 not defined.
Traceback (most recent call last):
  File "./mno.py", line 3907, in <module>
    prints_for_20240612()
  File "./mno.py", line 3904, in prints_for_20240612
    piece.build_print(track_selector, prints_dir=output_dir)
  File "/home/graffy/private/dev/pymusco/src/pymusco/piece.py", line 232, in build_print
    stub_to_print(
  File "/home/graffy/private/dev/pymusco/src/pymusco/main.py", line 429, in stub_to_print
    toto_pdf.add_page(track_page)
  File "/home/graffy/private/melting-notes/partitions/partitions.venv/lib/python3.8/site-packages/PyPDF2/_writer.py", line 321, in add_page
    return self._add_page(page, list.append, excluded_keys)
  File "/home/graffy/private/melting-notes/partitions/partitions.venv/lib/python3.8/site-packages/PyPDF2/_writer.py", line 271, in _add_page
    page = cast("PageObject", page_org.clone(self, False, excluded_keys))
  File "/home/graffy/private/melting-notes/partitions/partitions.venv/lib/python3.8/site-packages/PyPDF2/generic/_data_structures.py", line 181, in clone
    d__._clone(self, pdf_dest, force_duplicate, ignore_fields)
  File "/home/graffy/private/melting-notes/partitions/partitions.venv/lib/python3.8/site-packages/PyPDF2/generic/_data_structures.py", line 243, in _clone
    v.clone(pdf_dest, force_duplicate, ignore_fields)
  File "/home/graffy/private/melting-notes/partitions/partitions.venv/lib/python3.8/site-packages/PyPDF2/generic/_base.py", line 248, in clone
    assert obj is not None
AssertionError

[g-raffy]

Here's what I found until now:

• The bug seems to be revealed by the "hautbois 1" page, which is clearly different from other pages (it('s not an original track, it has been created by someone else, and has different properties: unlike the other pdf pages, it doesn't contain a /Group element)).
• the bug disappears when the stamps are not added
• the bug seems to be in pdftex, see [https://tex.stackexchange.com/questions/76273/multiple-pdfs-with-page-group-included-in-a-single-page-warning]

[g-raffy]

Here's a test function that exhibits the bug:

def bug_shower_1(trigger_bug: bool):
    src_pdf_file_path = Path('/home/graffy/private/melting-notes/partitions/scans/888-bug.pdf')

    tmp_dir = Path('/home/graffy/private/dev/pymusco/tickets/ticket0008/tmp')

    scanned_image_file_paths = []
    with open(src_pdf_file_path, 'rb') as src_pdf_file:
        pdf_reader = PyPDF2.PdfReader(src_pdf_file)
        page_index = 0
        for page in pdf_reader.pages:
            print(f'============= page_index = {page_index}')
            # image_file_path = extract_pdf_page_main_image(page, image_dir=tmp_dir, image_name=('page%03d' % page_index))
            image_file_path = extract_pdf_page(page, image_dir=tmp_dir, image_name=f'page{page_index:03d}')
            print(image_file_path)
            # check_pdf_file(image_file_path)

            scanned_image_file_paths.append(image_file_path)
            page_index += 1

    # stamp_descs = stamp_descs if stamp_descs is not None else []

    orchestra = load_orchestra('/home/graffy/private/dev/pymusco/samples/harmony.orchestra')

    piece = load_piece_description(Path('/home/graffy/private/melting-notes/partitions/scans/888-bug.desc'), orchestra)

    dst_stub_pdf_file_path = Path('/home/graffy/private/dev/pymusco/tickets/ticket0008/stub.pdf')
    toc = piece.scan_toc

    if trigger_bug:
        stamp_descs = piece.stamp_descs
    else:
        stamp_descs = []

    images_to_pdf(StubContents(image_file_paths=scanned_image_file_paths, toc=toc, title='toto', stamp_descs=stamp_descs, page_info_line_y_pos=1.0), dst_stub_pdf_file_path)

    # check_pdf_file(dst_stub_pdf_file_path)

    dst_stub_copy_pdf_file_path = Path('/home/graffy/private/dev/pymusco/tickets/ticket0008/stub-copy.pdf')
    duplicate_pdf_file_001(dst_stub_pdf_file_path, dst_stub_copy_pdf_file_path)
    # check_pdf_file(dst_pdf_file_path)