On 3/24/20 3:07 PM, Nick Bowler wrote:
On 2020-03-24, Ross Burton <r...@burtonini.com> wrote:
As to why this is not broken with 2.69, I think I have a theory.
If I build e.g. acl with both 2.69 and master, it's notable that 2.69
has these lines in the output that do not exist in master:
checking how to run the C preprocessor... gcc -E
checking for grep that handles long lines and -e...
/scratch/poky/hosttools/grep
checking for egrep... /scratch/poky/hosttools/grep -E
checking for ANSI C header files... yes
Probably that is it: the long-obsolete AC_HEADER_STDC, previously
used internally by AC_INCLUDES_DEFAULT, used AC_EGREP_HEADER. The
AC_HEADER_STDC macro is now a no-op (and is not used at all within
Autoconf anymore), so that change is likely what made the first use
of AC_EGREP_HEADER the one inside the if condition, causing the
observed results.
We already have autoupdate remove a call to AC_HEADER_STDC and replace
it with the direct side-effect results of setting STDC_HEADERS and
TIME_WITH_SYS_TIME; should we also tweak that to preserve the
side-effect of AC_REQUIRES([AC_EGREP_HEADER)], to minimize the pain on
external projects unaware that they were depending on that side-effect?
Or maybe just tweak the NEWS blurb to mention that users depending on
$GREP being set early may need to be careful?
--
Eric Blake, Principal Software Engineer
Red Hat, Inc. +1-919-301-3226
Virtualization: qemu.org | libvirt.org
