[Aptitude-devel] Bug#792681: cwidget ftbfs with GCC 5

[Matthias Klose]

On 07/17/2015 06:57 PM, Manuel A. Fernandez Montecelo wrote:
> Hello,
> 
> 2015-07-17 14:13 GMT+01:00 Matthias Klose <doko at debian.org>:
>> Package: src:cwidget
>> Version: 0.5.17-2
>> Severity: normal
>> Tags: sid stretch patch
>> User: debian-gcc at lists.debian.org
>> Usertags: ftbfs-gcc-5
>>
>> GCC 5 complains about using c++11 features without passing -std=c++11. Also
>> setting the maintainer flag without exporting it doesn't help.
>>
>> patch at
>> https://launchpadlibrarian.net/211899860/cwidget_0.5.17-2ubuntu1_0.5.17-2ubuntu2.diff.gz
> 
> If I found the correct build log where you determined this [1], the
> compiler fails when including
> 
> In file included from /usr/include/c++/5/string:52:0,
>                  from ../../../src/cwidget/curses++.h:25,
>                  from colors.cc:22:
> 
> Line 22 of colors is:
> #include <cwidget/curses++.h>
> 
> And line 25 of curses++.h is:
> #include <string>
> 
> The error is:
> -----------------------
> /usr/include/c++/5/bits/basic_string.h: In instantiation of 'union
> std::__cxx11::basic_string<cwidget::wchtype>::<anonymous>':
> /usr/include/c++/5/bits/basic_string.h:119:7:   required from 'class
> std::__cxx11::basic_string<cwidget::wchtype>'
> ../../../src/cwidget/curses++.h:199:31:   required from here
> /usr/include/c++/5/bits/basic_string.h:121:53: error: member
> 'cwidget::wchtype
> std::__cxx11::basic_string<cwidget::wchtype>::<anonymous
> union>::_M_local_buf [1]' with constructor not allowed in union
>   _CharT           _M_local_buf[_S_local_capacity + 1];
>                                                      ^
> /usr/include/c++/5/bits/basic_string.h:121:53: note: unrestricted
> unions only available with -std=c++11 or -std=gnu++11
> -----------------------
> 
> This is because wchtype does not seem to be able to be used as part of
> unions inside basic_string.h because the constructors/destructors are
> not "trivial" enough.
> 
> I was trying to work around this for a while, because I think that
> forcing c++11 mode will have cascading effects on rev-deps (currently
> only one within Debian, but it is aptitude with almost 100% of
> reported installations by popcon), but I could not find a satisfactory
> solution yet.
> 
> Is there a deadline to fix this?

yes, Jul 31. please see my email to d-d-a.

> [1] https://people.debian.org/~doko/logs/gcc5-20150701-ftbfs/logs-failed-gcc5/cwidget_0.5.17-2_unstable_gcc5.log

this was the error I saw:

Making all in config
make[5]: Entering directory
'/scratch/packages/tmp/cwidget-0.5.17/src/cwidget/config'
/bin/bash ../../../libtool  --tag=CXX   --mode=compile g++
-DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -I. -I../../..  -Wall -Werror
-I../../.. -I. -I../../.. -I../../../src -D_FORTIFY_SOURCE=2  -g -O2
-fstack-protector-strong -Wformat -Werror=format-security -D_REENTRANT
-I/usr/include/sigc++-2.0 -I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include  -c -o
colors.lo colors.cc
libtool: compile:  g++ -DLOCALEDIR=\"/usr/share/locale\" -DHAVE_CONFIG_H -I.
-I../../.. -Wall -Werror -I../../.. -I. -I../../.. -I../../../src
-D_FORTIFY_SOURCE=2 -g -O2 -fstack-protector-strong -Wformat
-Werror=format-security -D_REENTRANT -I/usr/include/sigc++-2.0
-I/usr/lib/x86_64-linux-gnu/sigc++-2.0/include -c colors.cc  -fPIC -DPIC -o
.libs/colors.o
In file included from /usr/include/c++/5/string:52:0,
                 from ../../../src/cwidget/curses++.h:25,
                 from colors.cc:22:
/usr/include/c++/5/bits/basic_string.h: In instantiation of 'union
std::__cxx11::basic_string<cwidget::wchtype>::<anonymous>':
/usr/include/c++/5/bits/basic_string.h:119:7:   required from 'class
std::__cxx11::basic_string<cwidget::wchtype>'
../../../src/cwidget/curses++.h:199:31:   required from here
/usr/include/c++/5/bits/basic_string.h:121:53: error: member 'cwidget::wchtype
std::__cxx11::basic_string<cwidget::wchtype>::<anonymous union>::_M_local_buf
[1]' with constructor not allowed in union
  _CharT           _M_local_buf[_S_local_capacity + 1];
                                                     ^
/usr/include/c++/5/bits/basic_string.h:121:53: note: unrestricted unions only
available with -std=c++11 or -std=gnu++11
Makefile:448: recipe for target 'colors.lo' failed
make[5]: *** [colors.lo] Error 1
make[5]: Leaving directory '/scratch/packages/tmp/cwidget-0.5.17/src/cwidget/config'
Makefile:603: recipe for target 'all-recursive' failed
make[4]: *** [all-recursive] Error 1