determine_architectures_to_build creates no builds for arch-indep source when nominatedarchindep is unbuildable

[James Troup]

I have a trusty PPA with i386 disabled; AIUI when I upload a source
package which has architecture all binaries the source package should
get built on amd64. However, that's not what happens, instead I get
an 'Accepted' mail which complains that it can't build the
architecture all binary and the upload is discarded.

This is an example of such a mail:

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Date: Wed, 30 Dec 2015 22:18:15 -0000
From: Launchpad PPA <email address hidden>
To: James Troup <email address hidden>
Subject: [~elmo/ubuntu/prometheus/trusty] golang-golang-x-net-dev 1:0.0+git20150817.66f0418-1ppa2 (Accepted)

Accepted:
 OK: golang-golang-x-net-dev_0.0+git20150817.66f0418.orig.tar.gz
 OK: golang-golang-x-net-dev_0.0+git20150817.66f0418-1ppa2.debian.tar.gz
 OK: golang-golang-x-net-dev_0.0+git20150817.66f0418-1ppa2.dsc
     -> Component: main Section: devel
Cannot build any of the architectures requested: all

golang-golang-x-net-dev (1:0.0+git20150817.66f0418-1ppa2) trusty; urgency=low

  * No change upload to force a build on amd64.

--
https://launchpad.net/~elmo/+archive/ubuntu/prometheus
You are receiving this email because you made this upload.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

[William Grant (wgrant)]

The erroneous Accepted email is bug #1530220.

[William Grant (wgrant)]

determine_architectures_to_build will only ever add nominatedarchindep to the architectures specified by the hintlist. We should probably prefer nominatedarchindep but fall back to the full list in usual by-ID order if it's unavailable.

[Launchpad QA Bot (lpqabot)]

Fixed in stable r17879 <http://bazaar.launchpad.net/~launchpad-pqm/launchpad/stable/revision/17879>.