Re: [PATCH v1 2/2] Define SOURCE_DATE_EPOCH based on git log

[Julien Grall <julien@xxxxxxx>]

On 03/11/2020 10:05, Jan Beulich wrote:
> On 03.11.2020 11:00, Julien Grall wrote:
> > Hi Frédéric,
> >
> > On 31/10/2020 15:14, Frédéric Pierret (fepitre) wrote:
> > > ---
> > >    xen/Makefile | 2 ++
> > >    1 file changed, 2 insertions(+)
> > >
> > > diff --git a/xen/Makefile b/xen/Makefile
> > > index 30b1847515..4cc35556ef 100644
> > > --- a/xen/Makefile
> > > +++ b/xen/Makefile
> > > @@ -6,6 +6,8 @@ export XEN_EXTRAVERSION ?= -unstable$(XEN_VENDORVERSION)
> > >    export XEN_FULLVERSION   = 
> > > $(XEN_VERSION).$(XEN_SUBVERSION)$(XEN_EXTRAVERSION)
> > >    -include xen-version
> > >    
> > > +export SOURCE_DATE_EPOCH	?= $(shell git log -1 --format=%ct 2>/dev/null)
> > It is possible to download a tarball for Xen release (see [1]). They
> > don't contain the .git directory and therefore this command would fail.
> >
> > Should we fallback to "date" in this case?
> Isn't this what already happens? The variable would be assigned
> an empty value in this case, wouldn't it?
My question was whether empty SOURCE_DATE_EPOCH is acceptable?

Looking at patch #1, the users of the variable will use "date" if it is 
empty. Why can't this behavior be common?
Cheers,

--
Julien Grall