Re: [boost] Libc++ failures on linux

Subject: Re: [boost] Libc++ failures on linux
From: Tom Kent (lists_at_[hidden])
Date: 2017-03-16 01:57:00

On Sat, Mar 11, 2017 at 9:43 PM, Tom Kent <lists_at_[hidden]> wrote:

>
>
> On Fri, Mar 10, 2017 at 7:43 PM, Andrey Semashev via Boost <
> boost_at_[hidden]> wrote:
>
>> On Sat, Mar 11, 2017 at 3:32 AM, Deniz Bahadir via Boost
>> <boost_at_[hidden]> wrote:
>> > Am 11.03.2017 um 00:22 schrieb Andrey Semashev via Boost:
>> >>
>> >> /usr/include/c++/v1/string:1938:44: error: 'basic_string<_CharT,
>> >> _Traits, _Allocator>' is missing exception specification 'noexcept'
>> >> basic_string<_CharT, _Traits, _Allocator>::basic_string(const
>> >> allocator_type& __a)
>> >>                                            ^
>> >> /usr/include/c++/v1/string:1326:40: note: previous declaration is here
>> >>     _LIBCPP_INLINE_VISIBILITY explicit basic_string(const
>> allocator_type&
>> >> __a)
>> >>
>> >> This happens after boost/config.hpp is included, which means that
>> >> cstddef is found. Indeed, cstddef is in /usr/include/c++/v1 on my
>> >> system, so the compiler clearly looks there.
>> >>
>> >> The error itself looks like a bug in libc++.
>> >
>> > This is a known error on Ubuntu/Debian:
>> > https://bugs.launchpad.net/ubuntu/+source/libc++/+bug/1610168
>> >
>> > And the fix is simple, presuming one can modify header-files of the
>> libc++
>> > installation:
>> > http://stackoverflow.com/a/38385967
>>
>> I guess, one could make a local change like that, but modifying system
>> headers is generally a bad idea and can't be recommended. I mean, even
>> if Tom makes the change on the test machine, that doesn't make Boost
>> actually work on users' machines. Which means libc++ can not be
>> officially supported.
>>
>> >> /usr/include/c++/v1/cxxabi.h:21:10: fatal error: '__cxxabi_config.h'
>> >> file not found
>> >> #include <__cxxabi_config.h>
>> >>
>> >> This error is more interesting. I can see this #include in my local
>> >> libc++ as well, yet I can't find this file on my system.
>> >
>> > On my Ubuntu machine I was able to fix this error by adding the
>> following
>> > path to the include-search-path: /usr/include/libcxxabi
>> >
>> > If you do not have this path on your Ubuntu/Debian machine, you need to
>> > install libc++abi, too. (DEB-Package: libc++abi-dev)
>>
>> Right, which makes it a packaging bug, because the package should have
>> been pulled as a dependency of libc++-dev.
>>
>> > Hope that helps,
>>
>> It does, thanks.
>
>
>
> Installing the baseline ubuntu libc++abi-dev *and* adding
> `-I/usr/include/libcxxabi` to my user-config.jam file got rid of the file
> not found #include <__cxxabi_config.h>
> Once I get a chance to make a decent solution, I'm going to put a fix in
> my docker image for the `/usr/include/c++/v1/string:1938:44: error:
> 'basic_string<...` issue.
>

Seems to have worked out now. I've got the fix into my docker builds, and
the libc++ runners are cycling. See teeks99-02-dc3.0-1z-lc and
teeks99-02-mc3.9-1z-lc for develop and master tests.

Tom