Bug#923467: libvigraimpex: FTBFS (Could not import extension sphinx.ext.pngmathCould not import extension sphinx.ext.pngmath)

[Santiago Vila]

Package: src:libvigraimpex
Version: 1.10.0+git20160211.167be93+dfsg1-1
Severity: serious
Tags: ftbfs

Dear maintainer:

I tried to build this package in buster but it failed:

--------------------------------------------------------------------------------
[...]
 debian/rules build-indep
make: Nothing to be done for 'build-indep'.
 fakeroot debian/rules binary-indep
dh_testdir
dh_testroot
/usr/bin/make -f debian/rules doc/vigra/build-stamp
make[1]: Entering directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1'
mkdir -p obj/
cd obj/ && cmake .. -DCMAKE_INSTALL_PREFIX=/usr -DLIB_SUFFIX="/x86_64-linux-gnu/" -DCMAKE_VERBOSE_MAKEFILE=ON -DWITH_OPENEXR=ON -DCMAKE_C_FLAGS_RELEASE="-g -O2 -fdebug-prefix-map=/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1=. -fstack-protector-strong -Wformat -Werror=format-security -pipe -Wdate-time -D_FORTIFY_SOURCE=2" -DCMAKE_CXX_FLAGS_RELEASE="-g -O2 -fdebug-prefix-map=/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1=. -fstack-protector-strong -Wformat -Werror=format-security -pipe -Wdate-time -D_FORTIFY_SOURCE=2" -DCMAKE_SHARED_LINKER_FLAGS_RELEASE="-Wl,-z,relro -Wl,--as-needed -Wl,-z,now"  -DPYTHON_EXECUTABLE=/usr/bin/python -DWITH_VIGRANUMPY=0
-- The C compiler identification is GNU 8.2.0
-- The CXX compiler identification is GNU 8.2.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info

[... snipped ...]

/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/classvigra_1_1VolumeExportInfo.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/classvigra_1_1HDF5Handle.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/ErrorReporting.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/group__StandardImageTypes.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/NumericPromotionTraits.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/group__NonLinearDiffusion.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/classvigra_1_1SIFImportInfo-members.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/classvigra_1_1GaborFilterFamily-members.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/classvigra_1_1acc_1_1Central_3_01PowerSum_3_012_01_4_01_4-members.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/Tutorial.html
/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/PromoteTraits.html
cd /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/docsrc && /usr/bin/cmake -E copy_directory /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/docsrc/documents /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/documents
cd /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/docsrc && /usr/bin/cmake -E copy_if_different /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/docsrc/../LICENSE.txt /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/LICENSE.txt
cd /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/docsrc && /usr/bin/cmake -E copy_if_different /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/docsrc/../src/matlab/doc/tutorial_reference.pdf /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigra/documents/tutorial_reference.pdf
make[5]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
[100%] Built target doc_cpp
/usr/bin/make -f vigranumpy/docsrc/CMakeFiles/doc_python.dir/build.make vigranumpy/docsrc/CMakeFiles/doc_python.dir/depend
make[5]: Entering directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
cd /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7 && /usr/bin/cmake -E cmake_depends "Unix Makefiles" /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1 /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/vigranumpy/docsrc /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7 /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/vigranumpy/docsrc /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/vigranumpy/docsrc/CMakeFiles/doc_python.dir/DependInfo.cmake --color=
Scanning dependencies of target doc_python
make[5]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
/usr/bin/make -f vigranumpy/docsrc/CMakeFiles/doc_python.dir/build.make vigranumpy/docsrc/CMakeFiles/doc_python.dir/build
make[5]: Entering directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
[100%] Generating vigranumpy documentation
cd /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/vigranumpy/docsrc && /usr/bin/cmake -E make_directory /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigranumpy
cd /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/vigranumpy/docsrc && /usr/bin/sphinx-build -b html -d /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigranumpy/doctrees -D latex_paper_size=a4 -c /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/vigranumpy/docsrc /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/vigranumpy/docsrc /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/doc/vigranumpy
Running Sphinx v1.8.4

Extension error:
Could not import extension sphinx.ext.pngmath (exception: No module named 'sphinx.ext.pngmath')
Working directory: /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/vigranumpy
vigraimpex path: /<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7/src/impex
make[5]: *** [vigranumpy/docsrc/CMakeFiles/doc_python.dir/build.make:62: vigranumpy/docsrc/CMakeFiles/doc_python] Error 2
make[5]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
make[4]: *** [CMakeFiles/Makefile2:4311: vigranumpy/docsrc/CMakeFiles/doc_python.dir/all] Error 2
make[4]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
make[3]: *** [CMakeFiles/Makefile2:4318: vigranumpy/docsrc/CMakeFiles/doc_python.dir/rule] Error 2
make[3]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
make[2]: *** [Makefile:1370: doc_python] Error 2
make[2]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1/obj.python2.7'
make[1]: *** [debian/rules:169: doc/vigranumpy/build-stamp] Error 2
rm obj.python2.7/CMakeCache.txt
make[1]: Leaving directory '/<<BUILDDIR>>/libvigraimpex-1.10.0+git20160211.167be93+dfsg1'
make: *** [debian/rules:147: binary-indep] Error 2
dpkg-buildpackage: error: fakeroot debian/rules binary-indep subprocess returned exit status 2
--------------------------------------------------------------------------------

(The above is just how the build ends and not necessarily the most relevant part)

The build was made in my autobuilder with "dpkg-buildpackage -A"
and it also fails here:

https://tests.reproducible-builds.org/debian/rb-pkg/unstable/amd64/libvigraimpex.html

where you can get a full build log if you need it.

If this is really a bug in one of the build-depends, please use reassign and affects,
so that this is still visible in the BTS web page for this package.

Thanks.