[Qa-jenkins-dev] Bug#897662: reproducible: is localhost unresolvable in the build chroot?

[Simon McVittie]

Package: jenkins.debian.org
Severity: normal

dbus has been failing to build on reproducible.debian.org for a while,
with test failures. In the version in experimental (which has better
diagnostics for unexpected errors in testing) I see[1]:

    Failed to lookup host/port: "localhost:0": Name or service not known (-2)

Is this accurate? Is `getent hosts localhost` something that is expected
to fail in the reproducible-builds chroots?

If so, I don't think that's a good idea. Resolving arbitrary DNS names
and contacting remote machines is not something that a build should be
doing; but if we want to run build-time tests for anything that does
networking, then I don't think these actions should be counted as network
access:

* resolving the reserved name "localhost" to 127.0.0.1 and/or ::1
* listening on 127.0.0.0/8
* listening on ::1
* connecting to servers started by the build-time tests on those addresses
* generally making use of the "lo" interface

I would tend to consider those to be part of the (admittedly
loosely-defined) API of a correctly configured Linux system, rather than
being networking.

As a result, I think build chroots should have a conventional /etc/hosts
available.

    smcv

[1] If you read the log, please ignore the
    org.freedesktop.DBus.Error.AddressInUse part, which appears to be a
    dbus bug <https://bugs.freedesktop.org/show_bug.cgi?id=106395> but is
    not important here.