Bug#869506: Please don't drop environment variables

[Russ Allbery]

Guido Günther <agx at sigxcpu.org> writes:
> On Sun, Jul 23, 2017 at 11:43:02PM +0200, Raphaël Halimi wrote:

>> After reading all of those links, I'm all the more convinced that
>> cleaning the environment should be pbuilder's job, and not gbp's. All
>> environment variables given by the user should be passed on to pbuilder
>> as-is, since the latter needs them to properly set its directories (I
>> guess most people follow one of those wikis when they install pbuilder
>> for the first time), but if a clean environment must be passed to the
>> chroot, IMHO it would be pbuilder's responsibility to do that.

> Russ, do you have an opinion on this one. The generic variable names are
> imho calling for trouble (although they're very convenient to type). We
> could still accept them in git-pbuilder but only pass on GIT_PBUILDER_
> prefixed ones.  Only cleaning out these three variables in pbuilder
> itself looks special cased either.

The original thought process for the DIST and ARCH environment variables
was that there was otherwise no way to configure this from the command
line, and I wanted something short and easy to type.

Now that git-pbuilder has been more thoroughly integrated into
git-buildpackage and the --git-dist and --git-arch flags exist, I think it
makes a lot of sense to namespace these environment variables under
GIT_PBUILDER_ and stop using the very generic names that may get in the
way of other software.

There's a transition for people who are used to typing DIST=stable gbp
buildpackage instead of gbp buildpackage --git-dist=stable, but a note in
NEWS.Debian is probably sufficient.

-- 
Russ Allbery (rra at debian.org)               <http://www.eyrie.org/~eagle/>