[Qa-jenkins-dev] Bug#888099: reproducible: Please consider doing separate arch/indep builds in build2

[Simon McVittie]

Package: jenkins.debian.org
Severity: wishlist

When Debian developers follow best practices (source-only uploads), the
production Debian buildd infrastructure builds architecture-specific
packages and architecture-independent packages in two separate sbuild
invocations (dpkg-buildpackage -B, dpkg-buildpackage -A). This is not
particularly efficient (upstream source code normally ends up being
built twice), but amd64 buildd time is cheap.

However, reproducible-builds currently builds both sorts of package
together (dpkg-buildpackage -b). This can result in different bugs being
visible, for instance #887664 and which can be reproduced with -b but not
with -A or -B. I could also imagine it producing different built results.

For packages that build both Architecture: all and Architecture: any
(or packages of a specific architecture), it would be interesting for
"build2" to do two separate builds like the production buildd/sbuild
infrastructure does, then glue them together with mergechanges. This
would usually result in different .changes and .buildinfo files (which
should be treated as not a reproducibility failure, because the .changes
file is not consumed by end-users anyway) but would hopefully produce
identical binary packages.

    smcv