rst2pdf: rst2pdf crashes with several documents from the Linux Kernel

Trying to build pdf docs from Linux .rst files doesn’t work.

Description of problem

Cloning this tree, which contains a patch adding rst2pdf support:

https://git.linuxtv.org/mchehab/experimental.git/log/?h=rst2pdf-v3

and building the documentation with:

   $ git clone git://linuxtv.org/mchehab/experimental.git -b rst2pdf-v3
   $ make rst2pdf

Should create 71 pdf files under Documentation/output/pdf directory. 18 of them have zero size, because rst2pdf crashed.

This is an example of one of such crashes.

[ERROR] pdfbuilder.py:159 Failed to build doc
Traceback (most recent call last):
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/rst2pdf/pdfbuilder.py", line 156, in write
    docwriter.write(doctree, destination)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/docutils/writers/__init__.py", line 78, in write
    self.translate()
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/rst2pdf/pdfbuilder.py", line 672, in translate
    createpdf.RstToPdf(
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/rst2pdf/createpdf.py", line 659, in createPdf
    pdfdoc.multiBuild(elements)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/platypus/doctemplate.py", line 1177, in multiBuild
    self.canv.save()
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfgen/canvas.py", line 1277, in save
    self._doc.SaveToFile(self._filename, self)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 219, in SaveToFile
    data = self.GetPDFData(canvas)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 245, in GetPDFData
    return self.format()
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 427, in format
    IOf = IO.format(self)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 876, in format
    fcontent = format(self.content, document, toplevel=1)   # yes this is at top level
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 80, in format
    f = element.format(document)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 1613, in format
    return D.format(document)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 683, in format
    L = [(format(PDFName(k),document)+b" "+format(dict[k],document)) for k in keys]
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 683, in <listcomp>
    L = [(format(PDFName(k),document)+b" "+format(dict[k],document)) for k in keys]
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 80, in format
    f = element.format(document)
  File "/devel/v4l/docs/sphinx_2.4.4/lib64/python3.9/site-packages/reportlab/pdfbase/pdfdoc.py", line 1778, in format
    if f is None: raise ValueError("format not resolved, probably missing URL scheme or undefined destination target for '%s'" % self.name)
ValueError: format not resolved, probably missing URL scheme or undefined destination target for 'sleeping-things'

🖥 Versions

$ python -V
Python 3.9.0
$ pip freeze | grep -E '(rst2pdf|reportlab|[Ss]phinx)'
reportlab==3.5.56
rst2pdf==0.98
Sphinx==2.4.4
sphinx-rtd-theme==0.5.0
sphinxcontrib-applehelp==1.0.2
sphinxcontrib-devhelp==1.0.2
sphinxcontrib-htmlhelp==1.0.3
sphinxcontrib-jsmath==1.0.1
sphinxcontrib-qthelp==1.0.3
sphinxcontrib-serializinghtml==1.1.4

Tested on Fedora 33.