Re: [XEN PATCH v2] docs: set date to SOURCE_DATE_EPOCH if available

[Wei Liu <wl@xen.org>]

On Thu, Dec 24, 2020 at 08:02:37PM +0100, Hans van Kranenburg wrote:
> Hi,
> 
> On 12/23/20 5:56 PM, Maximilian Engelhardt wrote:
> > check if a GNU date that supports the '-u -d @...' options and syntax or
> > a BSD date are available. If so, use the appropriate options for the
> > date command to produce a custom date if SOURCE_DATE_EPOCH is defined.
> > If SOURCE_DATE_EPOCH is not defined or no suitable date command was
> > found, use the current date. This enables reproducible builds.
> > 
> > Signed-off-by: Maximilian Engelhardt <maxi@daemonizer.de>
> > 
> > Changes in v2:
> > - add capability detection for the 'date' command using ax_prog_date.m4
> > - add information about detected date command to config/Docs.mk
> > - only call a supported date command in docs/Makefile
> > ---
> > Please note the ax_prog_date.m4 macro is taken from the autoconf-archive
> > repository [1] and it's license is GPL v3 or later with an exception for
> > the generated configure script.
> > 
> > [1] https://www.gnu.org/software/autoconf-archive/
> > ---
> >  config/Docs.mk.in  |   3 +
> >  docs/Makefile      |  16 +++-
> >  docs/configure     | 213 +++++++++++++++++++++++++++++++++++++++++++++
> >  docs/configure.ac  |   9 ++
> >  m4/ax_prog_date.m4 | 139 +++++++++++++++++++++++++++++
> >  5 files changed, 379 insertions(+), 1 deletion(-)
> >  create mode 100644 m4/ax_prog_date.m4
> 
> Wait, what. The comment about the -d option already existing since 2005
> (in the previous thread) is relevant here...
> 
> I guess there would be other reasons why the whole current Xen master
> branch would not compile on e.g. Debian Sarge 3.1 from 2005... Like,
> amd64 did not even exist as release architecture yet, back then...
> 
> I'd prefer
> 
>   1 file changed, 7 insertions(+), 1 deletion(-)
> 
> over
> 
>   5 files changed, 379 insertions(+), 1 deletion(-)
> 
> in this case.
> 

I have not read the previous thread. I would rather prefer a smaller
patch than a larger one. I agree with Hans here.

Maximilian, what do you think?

Wei.