Thanks Nick and Peter for your analysis.
Yes, the "AC_" prefix fooled me, that AC_CHECK_DEFINE belongs to autoconf.
> On 2023-09-23, Nick Bowler wrote:
> > On 2023-09-23, Detlef Riekenberg wrote:
> >> AC_CHECK_DEFINE(__unix, CFLAGS="-DFOUND__unix $CFLAGS")
> >> AC_CHECK_DEFINE(__unix__, CFLAGS
> > On 24/9/23 11:03, Nick Bowler wrote:
> >> The word AC_CHECK_DEFINE is not found anywhere in the Autoconf
> >> source code or documentation.
> >
> > My guess would be that the 3rd party is the autoconf archive because
> > they provide both AX_CHECK_DEFINE and AC_CHECK_DEFINE
> >
> > http://git.s
