Re: What to do about /etc/debian_version

[Santiago Vila <sanvila@unex.es>]

Joey Hess wrote:
> Santiago Vila wrote:
> > In short: The reason you want to change /etc/debian_version is really
> > a technical one or it is purely aesthetical (which is what I suspect)?
>
> I know that the system is and will be running unstable in the future.
> I'm the only admin. So I'm probably the best authority on exactly what
> version of debian it is running, so why not let me edit the file to
> reflect that?

I ask again: What for? Is /etc/issue not enough for this "reflect" thing?

You say this file is a "configuration file", but configuration files
are usually read by programs to control their behaviour. Which is the
program whose behaviour you want to change? Nobody knows in fact who
and how the contents of this file will be used, so we don't know the
real effects of modifying it. We can imagine, however, that putting
something other than "2.2" or "testing/unstable" could potentially
break any script or program which expects /etc/debian_version to be
either "2.2" or "testing/unstable" (since this is what base-files provides).
In this case not only there is no benefit from changing the file but
it could be even harmful.

So: Is there a *technical* reason to change /etc/debian_version other
than it being just "nicer"?

> > By a change in the behaviour I mean a change in the "specs" :-)
> > i.e. going from "this file is warranted to be the same as the one
> > coming from the most recently installed base-files package" to "this
> > file is not always warranted to be the same...".
>
> Ah, but that is not true at all. Ways that a determined person or
> package can make /etc/debian_version not be the same right now:
>
> * divert it, replace with your own file
> * modify it every 5 minutes in a cron job
> * install a locally compiled base-files

Ok, I will complete the specs: "This file is warranted, etc. etc. on a
system which has not been `manipulated'". (by whatever sensible
definition of `manipulated' you choose, for example, any that makes
`manipulated' systems unsuitable for being an autobuilder).

In either case, the examples you mention are all "complex" things that
probably only an experienced user (like you) would do. If you know how
to do these things, why do you need /etc/debian_version to be a conffile?

> > If we can't safely assume that /etc/debian_version comes directly from
> > base-files, then it is when this file begins to be really useless.
>
> Then it must have always been useless. Except, I have actually found it
> useful (see examples on the thread a few days ago).

But I have yet to see what "aestheticallity" (as opposed to functionality)
of /etc/debian_version is not already provided by /etc/issue.