[Pkg-octave-devel] Bug#831120: octave: FTBFS with GCC 6: array/Range.cc:498:21: error: 'floor' is not a member of 'gnulib'

[Lucas Nussbaum]

Source: octave
Version: 4.0.3-1
Severity: serious
Tags: stretch sid
User: debian-qa at lists.debian.org
Usertags: qa-ftbfs-20160713 qa-ftbfs
Justification: FTBFS with GCC 6 on amd64

Hi,

During a rebuild of all packages in sid using the gcc-defaults package
available in experimental to make GCC default to version 6, your package failed
to build on amd64. For more information about GCC 6 and Stretch, see:
- https://wiki.debian.org/GCC6
- https://lists.debian.org/debian-devel-announce/2016/06/msg00007.html

Relevant part (hopefully):
> /bin/bash ../libtool  --tag=CXX   --mode=compile g++ -DHAVE_CONFIG_H -I. -I..  -I./array -I./cruft/misc -Inumeric -I./numeric -Ioperators -I./operators -I./system -I./util -I../libgnu -I../libgnu          -Wdate-time -D_FORTIFY_SOURCE=2 -pthread -fopenmp -Wall -W -Wshadow -Wold-style-cast -Wformat -Wpointer-arith -Wwrite-strings -Wcast-align -Wcast-qual -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -c -o array/array_libarray_la-Range.lo `test -f 'array/Range.cc' || echo './'`array/Range.cc
> libtool: compile:  g++ -DHAVE_CONFIG_H -I. -I.. -I./array -I./cruft/misc -Inumeric -I./numeric -Ioperators -I./operators -I./system -I./util -I../libgnu -I../libgnu -Wdate-time -D_FORTIFY_SOURCE=2 -pthread -fopenmp -Wall -W -Wshadow -Wold-style-cast -Wformat -Wpointer-arith -Wwrite-strings -Wcast-align -Wcast-qual -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -c array/Range.cc  -fPIC -DPIC -o array/.libs/array_libarray_la-Range.o
> array/Range.cc: In function 'double tfloor(double, double)':
> array/Range.cc:498:21: error: 'floor' is not a member of 'gnulib'
>    double t1 = 1.0 + gnulib::floor (x);
>                      ^~~~~~
> array/Range.cc:498:21: note: suggested alternatives:
> In file included from ./util/oct-inttypes.h:34:0,
>                  from array/idx-vector.h:36,
>                  from array/Array.h:36,
>                  from array/MArray.h:28,
>                  from array/dNDArray.h:26,
>                  from array/dMatrix.h:26,
>                  from array/Range.h:28,
>                  from array/Range.cc:32:
> numeric/lo-mappers.h:282:1: note:   'floor'
>  floor (const std::complex<T>& x)
>  ^~~~~
> In file included from ./util/lo-math.h:27:0,
>                  from ./util/oct-inttypes.h:33,
>                  from array/idx-vector.h:36,
>                  from array/Array.h:36,
>                  from array/MArray.h:28,
>                  from array/dNDArray.h:26,
>                  from array/dMatrix.h:26,
>                  from array/Range.h:28,
>                  from array/Range.cc:32:
> /usr/include/c++/6/cmath:295:5: note:   'std::floor'
>      floor(_Tp __x)
>      ^~~~~
> array/Range.cc:502:8: error: 'floor' is not a member of 'gnulib'
>    t1 = gnulib::floor (x + t1);
>         ^~~~~~
> array/Range.cc:502:8: note: suggested alternatives:
> In file included from ./util/oct-inttypes.h:34:0,
>                  from array/idx-vector.h:36,
>                  from array/Array.h:36,
>                  from array/MArray.h:28,
>                  from array/dNDArray.h:26,
>                  from array/dMatrix.h:26,
>                  from array/Range.h:28,
>                  from array/Range.cc:32:
> numeric/lo-mappers.h:282:1: note:   'floor'
>  floor (const std::complex<T>& x)
>  ^~~~~
> In file included from ./util/lo-math.h:27:0,
>                  from ./util/oct-inttypes.h:33,
>                  from array/idx-vector.h:36,
>                  from array/Array.h:36,
>                  from array/MArray.h:28,
>                  from array/dNDArray.h:26,
>                  from array/dMatrix.h:26,
>                  from array/Range.h:28,
>                  from array/Range.cc:32:
> /usr/include/c++/6/cmath:295:5: note:   'std::floor'
>      floor(_Tp __x)
>      ^~~~~
> make[4]: *** [array/array_libarray_la-Range.lo] Error 1

The full build log is available from:
   http://people.debian.org/~lucas/logs/2016/07/13/octave_4.0.3-1_unstable_gcc6.log

A list of current common problems and possible solutions is available at
http://wiki.debian.org/qa.debian.org/FTBFS . You're welcome to contribute!

About the archive rebuild: The rebuild was done on EC2 VM instances from
Amazon Web Services, using a clean, minimal and up-to-date chroot. Every
failed build was retried once to eliminate random failures.