[gentoo-dev] Re: gcc-5 news item wrt C++ ABI

[Duncan <1i5t5.duncan@cox.net>]

Anthony G. Basile posted on Sat, 03 Oct 2015 19:53:14 -0400 as excerpted:

> On 10/3/15 7:16 PM, hasufell wrote:
>> On 10/03/2015 04:13 AM, Mike Frysinger wrote:
>>> Title: GCC 5 Defaults to the New C++11 ABI Author: Mike Frysinger
>>> <vapier@gentoo.org>
>>> Content-Type: text/plain Posted: 2015-10-02 Revision: 1
>>> News-Item-Format: 1.0 Display-If-Installed: >=sys-devel/gcc-5
>>>
>>> GCC 5 uses the new C++ ABI by default.  When building new code, you
>>> might run into link time errors like:
>>> ...: undefined reference to
>>> '_ZNSt6chrono12steady_clock3nowEv@GLIBCXX_3.4.17'
>>> Or you might see linkage failures with "std::__cxx11::string" in the
>>> output.
>>>
>>> These are signs that you need to rebuild packages using the new C++
>>> ABI.
>>> You can quickly do so by using revdep-rebuild like so:
>>> # revdep-rebuild --library 'libstdc\+\+\.so\.6'
>>>
>> We shouldn't assume a particular PM/toolset in news items, IMO. Just
>> saying that people might have to rebuild packages linked against
>> libstdc++.so.6 should be enough.
>>
>> They can read the docs if they don't know how.
>>
> Nothing precludes adding "see .... if you use paludis or clang."
> However, I'd like to see the above in there.

... Or simply...

 "If you have gentoolkit installed, you can quickly do so by using revdep-
rebuild like so:"...

I've seen that wording used before, and it seems reasonable enough to me, 
not assuming anything about whether it's installed, but giving at least 
some guidance to the folks who need it.

(If they don't have gentoolkit installed and don't know why, that it 
doesn't work with their PM or so, they probably simply followed the basic 
handbook install and are thus using portage.  In which case, that's a 
hint to install gentoolkit...  If they're using a PM other than portage, 
an assumption that they can read between the lines and make their own 
decisions on the merits is reasonable, given that they already did so in 
ordered to have that PM in the first place.)

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman