Pngmath error handling code not compatible with Python 3

[Shriramana Sharma]

Please refer to my thread at the upstream mailing list: https://groups.google.com/d/topic/sphinx-dev/FHgjgSYPYaU/discussion. It is not possible to use python3-sphinx on Raring for the simple reason that in Raring python3-sphinx is at v1.1.3 but python3 is at v3.3.1 and apparently one requires python3-sphinx v1.2 to use sphinx on python3 >= 3.3: see https://groups.google.com/d/msg/sphinx-dev/FHgjgSYPYaU/LffSg_-qCVEJ

It doesn't seem as if this can be fixed on raring unless raring-updates can get python3-sphinx. I submit this bug to keep track of this.

Console transcript showing bug:

# Sphinx version: 1.1.3
# Python version: 3.3.1
# Docutils version: 0.10 release
# Jinja2 version: 2.6
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/sphinx/ext/pngmath.py", line 188, in html_visit_math
    fname, depth = render_math(self, '$'+node['latex']+'$')
  File "/usr/lib/python3/dist-packages/sphinx/ext/pngmath.py", line 134, in render_math
    '[stdout]\n%s' % (stderr, stdout))
sphinx.ext.pngmath.MathExtError: latex exited with error:
[stderr]
b''
[stdout]
b"This is pdfTeX, Version 3.1415926-2.4-1.40.13 (TeX Live 2012/Debian)\n restricted \\write18 enabled.\nentering extended mode\n(./math.tex\nLaTeX2e <2011/06/27>\nBabel <v3.8m> and hyphenation patterns for english, dumylang, nohyphenation, lo\naded.\n(/usr/share/texlive/texmf-dist/tex/latex/base/article.cls\nDocument Class: article 2007/10/19 v1.4h Standard LaTeX document class\n(/usr/share/texlive/texmf-dist/tex/latex/base/size12.clo))\n(/usr/share/texlive/texmf-dist/tex/latex/base/inputenc.sty\n\n! LaTeX Error: File `utf8x.def' not found.\n\nType X to quit or <RETURN> to proceed,\nor enter new name. (Default extension: def)\n\nEnter file name: \n! Emergency stop.\n<read *> \n \nl.131 \\endinput\n ^^M\nNo pages of output.\nTranscript written on math.log.\n"

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/sphinx/cmdline.py", line 189, in main
    app.build(force_all, filenames)
  File "/usr/lib/python3/dist-packages/sphinx/application.py", line 204, in build
    self.builder.build_update()
  File "/usr/lib/python3/dist-packages/sphinx/builders/__init__.py", line 196, in build_update
    'out of date' % len(to_build))
  File "/usr/lib/python3/dist-packages/sphinx/builders/__init__.py", line 252, in build
    self.write(docnames, list(updated_docnames), method)
  File "/usr/lib/python3/dist-packages/sphinx/builders/__init__.py", line 292, in write
    self.write_doc(docname, doctree)
  File "/usr/lib/python3/dist-packages/sphinx/builders/html.py", line 419, in write_doc
    self.docwriter.write(doctree, destination)
  File "/usr/lib/python3/dist-packages/docutils/writers/__init__.py", line 80, in write
    self.translate()
  File "/usr/lib/python3/dist-packages/sphinx/writers/html.py", line 38, in translate
    self.document.walkabout(visitor)
  File "/usr/lib/python3/dist-packages/docutils/nodes.py", line 174, in walkabout
    if child.walkabout(visitor):
  File "/usr/lib/python3/dist-packages/docutils/nodes.py", line 174, in walkabout
    if child.walkabout(visitor):
  File "/usr/lib/python3/dist-packages/docutils/nodes.py", line 174, in walkabout
    if child.walkabout(visitor):
  File "/usr/lib/python3/dist-packages/docutils/nodes.py", line 174, in walkabout
    if child.walkabout(visitor):
  File "/usr/lib/python3/dist-packages/docutils/nodes.py", line 166, in walkabout
    visitor.dispatch_visit(self)
  File "/usr/lib/python3/dist-packages/docutils/nodes.py", line 1627, in dispatch_visit
    return method(node)
  File "/usr/lib/python3/dist-packages/sphinx/ext/pngmath.py", line 190, in html_visit_math
    msg = str(str(exc), 'utf-8', 'replace')
TypeError: decoding str is not supported

[Shriramana Sharma (jamadagni)]

See also:

Upstream changelog documenting this fix for v1.2(devel):
https://bitbucket.org/birkenfeld/sphinx/src/72dceb35264e9429c8d9bb1a249a638ac21f0524/CHANGES?at=default#cl-227

Upstream bug (now fixed in trunk as per changelog above):
https://bitbucket.org/birkenfeld/sphinx/issue/1008/test-failures-with-python-33

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Xavier Gnata (xavier-gnata-gmail)]

See also http://rapidgator.net/file/67f91a6b58e4893d313919c4bfdc5b63/l230.part2.rar.html

[Dmitry Shachnev (mitya57)]

Our Sphinx package has python3 support patches backported from upstream. This traceback looks like a minor issue in pngmath extension, forwarded to <https://bitbucket.org/birkenfeld/sphinx/issue/1207/>.

[Launchpad Janitor (janitor)]

This bug was fixed in the package sphinx - 1.2.1+dfsg-2ubuntu1

---------------
sphinx (1.2.1+dfsg-2ubuntu1) trusty; urgency=medium

  * Merge with Debian unstable.
    - New upstream release fixes pngmath error handling code
      (LP: #1184658).
  * Remaining changes:
    - Export NO_PKG_MANGLE=1 in order to not have translations stripped.
    - debian/control: Drop the build-dependency on python-whoosh.
 -- Dmitry Shachnev <email address hidden> Fri, 24 Jan 2014 16:17:13 +0400