On Wed, Aug 04, 2021 at 07:59:21AM +0200, Wolfgang Denk wrote:

> Dear Tom,
> 
> In message <20210802213100.GG9379@bill-the-cat> you wrote:
> > 
> > I think that if nothing changes the banner not changing is the right
> > behavior.
> 
> Hm... is it?  How about "external" changes like building with a
> different tool chain? Then at least the "version" command should
> produce a corresponding output, which means some parts _have_ to be
> recompiled, resulting in a new banner, too ?

There's some misunderstanding about what this series does, and does not
do.  First, with the series applied and you don't force
SOURCE_DATE_EPOCH, and you run make, and you re-run make, cmd/version.c
is rebuilt (but only that and not a bunch of other things anymore) and
the banner timestamp changes.  Second, if you do set SOURCE_DATE_EPOCH
to a fixed value (so you're trying to reproduce a build with a specific
timestamp) AND re-run make, nothing changes, as it should.  Third, if
you change gcc, everything gets rebuilt including cmd/version.c and a
new banner.

-- 
Tom