bug#62647: [INSTALL] grep: re-fix Y2038 bug on glibc 2.34+ x86, ARM

[Jim Meyering]

On Mon, Apr 3, 2023 at 10:34 AM Paul Eggert <eggert@cs.ucla.edu> wrote:
> The meaning of AC_SYS_LARGEFILE has changed to no longer even try
> to use wider time_t if available.  So use AC_SYS_YEAR2038 as well.
> A more-aggressive change would be to use the next Autoconf’s
> AC_SYS_YEAR2038_REQUIRED but at least let’s restore the grep 3.8
> behavior.
> * NEWS: Mention this.
> * bootstrap.conf: Add year2038.
> ---
>  NEWS           | 4 ++++
>  bootstrap.conf | 1 +
>  2 files changed, 5 insertions(+)
>
> diff --git a/NEWS b/NEWS
> index 6ebade3..060e938 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -10,6 +10,10 @@ GNU grep NEWS                                    -*- 
> outline -*-
>    grep 3.8, in that patterns like \w and \b use ASCII rather than
>    Unicode interpretations.
>
> +  grep no longer fails on files dated after the year 2038,
> +  when running on 32-bit x86 and ARM hosts using glibc 2.34+.
> +  [bug introduced in grep 3.9]
> +
>
>  * Noteworthy changes in release 3.10 (2023-03-22) [stable]
>
> diff --git a/bootstrap.conf b/bootstrap.conf
> index 50948a6..ec48c37 100644
> --- a/bootstrap.conf
> +++ b/bootstrap.conf
> @@ -102,6 +102,7 @@ windows-stat-inodes
>  xalloc
>  xbinary-io
>  xstrtoimax
> +year2038
>  '

Thanks, Paul.
I wanted to see how this would make grep fail, but don't
have convenient access to such hosts. Would this trigger the failure?

  touch -t 203901010000 f
  grep ^ f

How does it fail?