Bug(?) of libstdc++ (COW is still used)

[Takashi Yano]

Hi Achim,

On Sun, 16 Aug 2026 08:54:06 +0200
ASSI via Cygwin <cygwin@cygwin.com> wrote:

> Takashi Yano via Cygwin writes:
> > Is there any reason that libstdc++ on Cygwin still uses COW
> > (_GLIBCXX_USE_CXX11_ABI = 0 setting), even though it is inhibited
> > since C++11?
> 
> I've inherited it that way and the reason it has not been changed is
> still the same: Binary compatibility across binaries and (probably more
> imporantly) libraries that were compiled with different settings breaks.
> The Linux distributions avoided that outcome by a "rebuild the world"
> event, but we might not be able to do that, at least not easily.
> 
> So no, you should not be nilly-willy changing that definition if you
> compile a library that potentially gets used by other parts of Cygwin
> (it is supposed to work correctly if it is only used by your
> application).

I understand that casually setting _GLIBCXX_USE_CXX11_ABI=1 cae be
problematic. Instead, I'll add a workaround for CoW to glslang package.

Thansk for the advice.

-- 
Takashi Yano <takashi.yano@nifty.ne.jp>