On Thu, Feb 25, 2021 at 07:22:37PM +0100, Thomas Monjalon wrote:

There was an intent to define _GNU_SOURCE globally,
but it was not set in pkg-config for external applications.

Is this something that we really want to do, to force all external apps to
use _GNU_SOURCE when compiling? Do some of our header files rely on
definitions only available with _GNU_SOURCE? If so, we should probably look
to remove that dependency rather than mandating the define.