[Debian-astro-maintainers] Bug#1066317: montage: FTBFS: two_plane.c:680:8: error: implicit declaration of function ‘isnan’ [-Werror=implicit-function-declaration]

[Lucas Nussbaum]

Source: montage
Version: 6.0+dfsg-8
Severity: serious
Justification: FTBFS
Tags: trixie sid ftbfs
User: lucas at debian.org
Usertags: ftbfs-20240313 ftbfs-trixie ftbfs-impfuncdef

Hi,

During a rebuild of all packages in sid, your package failed to build
on amd64.

This is most likely caused by a change in dpkg 1.22.6, that enabled
-Werror=implicit-function-declaration. For more information, see
https://wiki.debian.org/qa.debian.org/FTBFS#A2024-03-13_-Werror.3Dimplicit-function-declaration

Relevant part (hopefully):
> gcc -g -O2 -Werror=implicit-function-declaration -ffile-prefix-map=/<<PKGBUILDDIR>>=. -fstack-protector-strong -fstack-clash-protection -Wformat -Werror=format-security -fcf-protection -fcommon -fPIC -ansi -I. -I../../include -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -Wdate-time -D_FORTIFY_SOURCE=2 -I/usr/include/wcstools -I/usr/include/freetype2  -c -o two_plane.o two_plane.c
> two_plane.c: In function ‘Initialize_TwoPlane’:
> two_plane.c:680:8: error: implicit declaration of function ‘isnan’ [-Werror=implicit-function-declaration]
>   680 |     if(isnan(invdet)){
>       |        ^~~~~
> cc1: some warnings being treated as errors
> make[4]: *** [<builtin>: two_plane.o] Error 1


The full build log is available from:
http://qa-logs.debian.net/2024/03/13/montage_6.0+dfsg-8_unstable.log

All bugs filed during this archive rebuild are listed at:
https://bugs.debian.org/cgi-bin/pkgreport.cgi?tag=ftbfs-20240313;users=lucas@debian.org
or:
https://udd.debian.org/bugs/?release=na&merged=ign&fnewerval=7&flastmodval=7&fusertag=only&fusertagtag=ftbfs-20240313&fusertaguser=lucas@debian.org&allbugs=1&cseverity=1&ctags=1&caffected=1#results

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!

If you reassign this bug to another package, please mark it as 'affects'-ing
this package. See https://www.debian.org/Bugs/server-control#affects

If you fail to reproduce this, please provide a build log and diff it with mine
so that we can identify if something relevant changed in the meantime.