[RFC] posix: Export posix_spawn_file_actions_{addchdir, addfchdir} (BZ 34437)

[Florian Weimer]

* Bruno Haible:

> Hi Adhemerval,
>
> Thank you for working on this.
>
>> it breaks our previous policy of not adding retroactively symbols.

And therefore this breaks versioned dependencies in most RPM-based
distributions.

> Why not version 2.44.1 ? I guess the symbol versioning mechanism must support
> version numbers of the form <major>.<minor>.<subminor>, because in the past,
> some symbols were assigned to versions GLIBC_2.3.3 or GLIBC_2.3.4, for
> instance.

We still have lots of old symbols like that.  But we don't really know
how software reacts to new symbols of that structure.

The gnulib problem occurs only after a rebuild.  An adverse reaction
to the 2.44.1 symbol structure might happen just after a glibc update,
with old applications.  Hard to tell beforehand if this is a good
trade-off.

A quick 2.45 release might be another option.

But I'm not quite convinced any of this is necessary.