[Reproducible-builds] Bug#832099: lintian: please check for unnecessary SOURCE_DATE_EPOCH assignments

[Niels Thykier]

Mattia Rizzolo:
> though, using dpkg-buildpackage is not mandatory, a package should be
> able to build with just `debian/rules binary`.  In such case SDE
> wouldn't be exported.
> 

To be honest, I am largely considering dpkg-buildpackage being optional
(for mandatory targets) as a great misfeature in our build system.  It
leads to us to duplicate logic or boilerplate in all packages rather
than just fixing this at the root.

> This looks fairly similar to e.g. DEB_HOST_ARCH & friends variables,
> that even if they are exported by dpkg-buildpackage you should set them
> in d/rules nonetheless.
> 
> At least, that's what my AM told me back then ^^

Indeed, that is still the correct thing to do right now.  However, I am
convinced that long term we might be better off challenging this
tradition.  I honestly do not see the major benefit that justifies this
level of code duplication.

Thanks,
~Niels