Problems with evolving feature test macros?

[Rich Felker]

On Tue, Mar 11, 2014 at 09:07:36AM -0700, Paul Eggert wrote:
> On 03/11/2014 07:44 AM, Michael Kerrisk (man-pages) wrote:
> >I'm guessing programmers will reach for
> >the only hammer that does not cause a compiler warning on any glibc
> >version:
> >
> >#define _GNU_SOURCE
> 
> That's what most application developers should do, who run into this
> problem.  There's even an Autoconf macro for it:
> AC_USE_SYSTEM_EXTENSIONS.
> 
> >That seems to be a very unfortunate situation.
> 
> It's typically only a minor annoyance.

No, it's very unfortunate because defining _GNU_SOURCE breaks
strerror_r, basename, and perhaps a few other functions I'm not
thinking of at the moment.

Rich