Re: [PATCH 4/4] environment: Add '--debug' flag.

[Leo Famulari]

On Tue, Jul 19, 2016 at 09:02:58PM +0200, David Craven wrote:
> > 1. I'd like to use overlay fs (like docker) and create a new overlay
> > for each phase to easily revert a phase.
> 
> I think this might also help to debug build reproducibility issues, by
> finding out which phase is introducing them. (Or is it always
> obvious?)

In general, the idea of being able to move between phases like that is
really cool. I don't have any experience with overlayfs, so I can't
comment on that detail.

I wouldn't say it's ever obvious where a reproducibility bug is
introduced, but many of them are timestamps, sometimes with an English
string attached, and that code is usually easy to find.

Thankfully, the Reproducible Builds project has a useful database of
bugs they've found:

https://anonscm.debian.org/git/reproducible/notes.git