Re: deleting rcs keywords from emacs sources

[Miles Bader <miles@gnu.org>]

On Tue, Mar 23, 2004 at 06:46:09PM +0000, spiegel@genion.de wrote:
> > if they're actively tracking CVS, they can easily
> > enough get the cvs revision with `cvs status').
> 
> Is that really the only answer?  To find out what version of a file you are 
> looking at, you need to be hooked up to the version control system?

In general, the version of a single file is not what you want for bug
reports, you want the state of the entire _system_.

There are several reasons for this, e.g. (a) it doesn't rely on the the
bug-reporter knowing what the relevant file is (which they often get wrong,
even if they think they do), and (b) many problems which manifest in a
particular piece of code are actually due to changes outside it, or
interactions between changes in both places.  Really you want bug reports to
come from M-x report-emacs-bug, unless the submitter is very knowledgeable,
as that will make sure to include other info that will tell you the state
more exactly.

If someone is using a packaged distribution of emacs, then it should be set
up to generate a meaningful emacs version number, which will tell you what
snapshot of the source tree it is from.

The only other common case (AFAIK) is that someone is actively tracking emacs
CVS; in this case, you probably _still_ want to know the state of the whole
system for the reasons stated above, but the version reported by M-x
emacs-version is not very useful (it effectively just tells you "CVS sometime
after this release").  However, you also know that in this case both that the
user has CVS info easily available, and is probably more knowledgable than
average (so probably _knows_ they have CVS info available).

So given this, I think we ought to (1) encourage people to use M-x
report-emacs-bug, (2) find a way to make M-x emacs-version give more useful
info for CVS checkouts (easy for arch though).

> I often send files back and forth, and frequently I need to decide what
> version I'm looking at, with the file being isolated from its version
> control history.

Er, if you're making changes outside of CVS than the keyword info isn't
going to be very useful, is it?

> I find it completely natural, even essential that a file is stamped with the 
> version it contains, the stamp being a part of the actual contents of the 
> file.

I've seen others say this too, and I suspect that's a major reason people use
rcs keywords -- it gives them warm fuzzies.

> It should be the job of the version control system to ignore this kind of
> changes for operations where it clearly doesn't make sense.  CVS, as
> somebody pointed out, is capable of this for the headers it produces.

It's too much of a tar pit: it means that the V.C.S. is _changing_ the
contents of the file, which is _dangerous_ (see the CVS documentation for
details); arch uses the much more robust model that what you put in is
exactly what you get out.

These keywords are the sort of thing that may seem like a great idea at
first, but which come back to haunt you later (as we now see :-)

-Miles
-- 
Somebody has to do something, and it's just incredibly pathetic that it
has to be us.  -- Jerry Garcia