Bug#831177: geos: FTBFS with GCC 6: ../../../include/geos/platform.h:114:2: error: #error "Can not compile without isnan function or macro"

[Lucas Nussbaum]

Source: geos
Version: 3.5.0-3
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++ -fpermissive -DHAVE_CONFIG_H -I. -I../../../include -I../../../include/geos  -I../../../include  -Wdate-time -D_FORTIFY_SOURCE=2 -DGEOS_INLINE  -pedantic -Wall -ansi -Wno-long-long  -ffloat-store -g -O2 -fPIE -fstack-protector-strong -Wformat -Werror=format-security -c -o IndexedPointInAreaLocator.lo IndexedPointInAreaLocator.cpp
> libtool: compile:  g++ -fpermissive -DHAVE_CONFIG_H -I. -I../../../include -I../../../include/geos -I../../../include -Wdate-time -D_FORTIFY_SOURCE=2 -DGEOS_INLINE -pedantic -Wall -ansi -Wno-long-long -ffloat-store -g -O2 -fstack-protector-strong -Wformat -Werror=format-security -c IndexedPointInAreaLocator.cpp  -fPIC -DPIC -o .libs/IndexedPointInAreaLocator.o
> In file included from ../../../include/geos/geom/Geometry.h:25:0,
>                  from IndexedPointInAreaLocator.cpp:17:
> ../../../include/geos/platform.h:114:2: error: #error "Can not compile without isnan function or macro"
>  #error "Can not compile without isnan function or macro"
>   ^~~~~
> In file included from ../../../include/geos/geom/Coordinate.h:158:0,
>                  from ../../../include/geos/geom/Envelope.h:25,
>                  from ../../../include/geos/geom/Geometry.h:27,
>                  from IndexedPointInAreaLocator.cpp:17:
> ../../../include/geos/geom/Coordinate.inl: In member function 'bool geos::geom::Coordinate::isNull() const':
> ../../../include/geos/geom/Coordinate.inl:38:17: error: 'ISNAN' was not declared in this scope
>   return (ISNAN(x) && ISNAN(y) && ISNAN(z));
>                  ^
> ../../../include/geos/geom/Coordinate.inl: In member function 'bool geos::geom::Coordinate::equals3D(const geos::geom::Coordinate&) const':
> ../../../include/geos/geom/Coordinate.inl:77:28: error: 'ISNAN' was not declared in this scope
>    ((z == other.z)||(ISNAN(z) && ISNAN(other.z)));
>                             ^
> make[7]: *** [IndexedPointInAreaLocator.lo] Error 1

The full build log is available from:
   http://people.debian.org/~lucas/logs/2016/07/13/geos_3.5.0-3_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.