Bug#904248: Beginnings of a patch to add netbase to build-essential

[Julien Cristau <jcristau@debian.org>]

On 08/04/2018 07:14 AM, Ian Jackson wrote:
> Sean Whitton writes ("Beginnings of a patch to add netbase to build-essential"):
>> Ian also thinks that package builds should be able to access the
>> information normally contained in /etc/protocols and /etc/services by
>> means of the C standard library.
> 
> Yes.
> 
>> Could you say more about why this is needed, and provide wording for a
>> third bullet point in the list in my patch, which describes the
>> functionality of /etc/protocols and /etc/services, please?
> 
> Sorry for the delay replying to this.
> 
> I think this is needed because some build systems look at
> /etc/{services,protocols} at build-time to (for example) bake into the
> program the default port number, or, in some cases, protocol numbers.
> The values in these files are largely fixed or conventional, so this
> is quite appropriate.  Expecting programs to add explicit dependencies
> on netbase for this seems silly - there is little benefit, since the
> files are small and the implementation of the lookup where done via
> the libc) is part of the libc.  And of course any notionally-missing
> dependencies on netbase would not be discovered.
> 
> I suggest this text:
> 
>   - for the package build to look up longstanding and conventionally
>     available service and protocol names and numbers, either by
>     directly reading /etc/services and /etc/protocols or by using the
>     corresponding functions from the C standard library.  (If the
>     package needs to look up a more recent service or protocol, and
>     certainly if the service or protocol was not listed in these files
>     in the package's targeted Debian releases, an appropriate
>     versioned build-dependency is needed.)
> 
FWIW I disagree, I expect this is rather nice usage and so requiring a
build-dep on netbase for the few packages that need this isn't a
problem.  Plus, these files being conffiles means you can't actually
rely on finding anything specific in there anyway.

Cheers,
Julien