Subject: Re: New virtual package names.

From: Dale Scheetz <[email-masked]>
Date: Thu, 1 Aug 1996 10:20:28 -0400 (EDT)

Well, it's been a while, so lets add:
imap-client and imap-server 
to the virtual package names list.

On another note, is there an editor virtual package? Is there any interest
in adding one? It could be valuable to add Provides: editor to ae (and
others as well).

Thanks,

Dwarf

------------                                          --------------

aka   Dale Scheetz                   Phone:   1 (904) 877-0257
      Flexible Software              Fax:     NONE 
      Black Creek Critters           e-mail:  [email-masked]

------------ If you don't see what you want, just ask --------------

---

From: Warwick HARVEY <[email-masked]>
Date: Fri, 02 Aug 1996 17:43:46 +1000

> to the virtual package names list.

Sure thing.  I'm not familiar with imap though, so could you give me a
description for these to go in the list?

> in adding one? It could be valuable to add Provides: editor to ae (and

What would it be used for?  Are there packages that depend on having an
editor, or for which it would be appropriate to recommend one (and have any
old editor serve the purpose)?  If so, no problem...

				Warwick

----------------------------------------------------------------------------
Warwick Harvey                                    email: [email-masked]
Department of Computer Science                        phone: +61-3-9287-9171
University of Melbourne                                 fax: +61-3-9348-1184
Parkville, Victoria, AUSTRALIA 3052     web: http://www.cs.mu.OZ.AU/~warwick

---

From: Lars Wirzenius <[email-masked]>
Date: Fri, 02 Aug 1996 13:59:46 +0300

Warwick HARVEY:
> Are there packages that depend on having an editor, 

Without trying, I think of vipw, vigr, mail, elm, rcs (and thus cvs),
trn, tin, and nn. I grant that all but vipw and vigr can be used without
an editor -- if you only read mail and news and never check anything in.

I don't have an opinion on whether an editor virtual package is needed,
though.

-- 
Lars Wirzenius <[email-masked]> <http://www.iki.fi/liw/>
Please don't Cc: me when replying to my message on a mailing list.

---

From: Dale Scheetz <[email-masked]>
Date: Fri, 2 Aug 1996 11:17:18 -0400 (EDT)

> old editor serve the purpose)?  If so, no problem...
Here is a better reason:

---------------------------------- paste begins --------------------------

>From [email-masked] Fri Aug  2 11:09:03 1996
Date: Thu, 1 Aug 1996 12:34:51 -0400
From: Daniel Quinlan <[email-masked]>
Reply-To: [email-masked], [email-masked]
To: [email-masked]
Subject: Bug#3994: ae won't deinstall
Resent-Date: Fri, 02 Aug 1996 11:03:06 GMT
Resent-From: Daniel Quinlan <[email-masked]>
Resent-To: [email-masked]
Resent-cc: Bruce Perens <[email-masked]>

Package: base
Version: 1.1.0-14

I'd like to be able to remove `ae', but it won't deinstall.  It should
be possible to remove ANY package if I really want to.  I don't like
it when I'm treated like a child by the packaging system.

---------------------------------- paste ends ---------------------------

So, if the base packages include a depends: editor and ae provides: editor
as well as vi, joe, emacs, and others. Then, as long as some package that
provides editor is installed, ae can be removed without difficulty.
(Actually I think the above problem is aleviated by removing ESSENTIAL
from ae, but the editor provides helps maintain the existance of some
editor on the system)

Later,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: [email-masked] (Kai Henningsen)
Date: 02 Aug 1996 18:47:00 +0200

> description for these to go in the list?

IMAP is to POP3 what Emacs is to ae.

MfG Kai

---

From: Ian Jackson <[email-masked]>
Date: Fri, 9 Aug 96 21:50 BST

Dale Scheetz writes ("Re: New virtual package names. "):
...
> in adding one? It could be valuable to add Provides: editor to ae (and

Sorry I'm coming into this so late (just over a week, in fact), but I
think this is a daft idea.

Noone is going to deinstall all the editors on their system and not
notice what they've done wrong and how to fix it - this is not the
kind of `mistake' our dependency scheme should try to address.

The only possible consequences of creating an `editor' virtual package
and having things depend on it are:
 * Needless updates to packages to add dependencies and Provides
 * Some person installs their own favourite editor in /usr/local
   and wants to remove all ours but can't.

I think the `editor' virtual package should be scrapped.

Ian.

---

From: Dale Scheetz <[email-masked]>
Date: Wed, 14 Aug 1996 11:10:16 -0400 (EDT)

> kind of `mistake' our dependency scheme should try to address.

It was my understanding that this was EXACTLY what dependancies were
designed for; Protecting the installer from removing functionality that
other packages need.

>  * Needless updates to packages to add dependencies and Provides

This is not a technical argument. It is an economic one, and should not be
listed as a primary point. (all change takes work) Your assertion that it
is needless is not yet backed up by technical arguments. In addition, the
modification of other editor packages to encorporate this new VPN are not
on any critical path, so they can happen as need arrises.

>    and wants to remove all ours but can't.

This is true for any package that has others that depend on it. If I want
to put a qmail of my own into /usr/local, I will still need to keep some
Debian mail-delivery-agent installed to satisfy other packages dependance
on an MDA. A way to tell dpkg about "non-package provides" would fix this
problem in general, but I don't necessarily think that it is needed, or
even desirable.

> I think the `editor' virtual package should be scrapped.
I personaly have no problem with this, as long as you can show a more
specific reason for doing so. So far I haven't seen an argument that is
"to the point".

Later,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: Ian Jackson <[email-masked]>
Date: Wed, 21 Aug 96 23:28 BST

...
> designed for; Protecting the installer from removing functionality that

Surely this is only useful if this is a mistake the user will be
likely to make, and then not know how to undo ?

> on any critical path, so they can happen as need arrises.

I can't prove that it's needless.  You're shifting the burden of
proof.  It's up to you to show that it's needed.

> problem in general, but I don't necessarily think that it is needed, or

The difference is that an editor is such a fundamental and
striaghtforward thing that it will be obvious to the user what they're
doing without the dependency scheme having to tell them.

You're using a sledgehammer to crack a probably-nonexistent nut.

Ian.

---

From: Dale Scheetz <[email-masked]>
Date: Thu, 22 Aug 1996 12:46:50 -0400 (EDT)

> proof.  It's up to you to show that it's needed.

The burden I am trying to shift onto your shoulders is for you to have
read the complete thread of this discussion. It is not clear that you have
done so. You declared the needlessness but gave no explanation of why this
was so.
The rest of us, as a group, have discussed this, at some length, and come
to the conclusion that the editor virtual package name was a viable
solution. As a late arrival to this discussion it is your responsibility
to have, at least, read the complete discussion, and speak to the points
raised and settled there. Blanket assertions without supporting arguments
are neither constructive, nor informative.

> You're using a sledgehammer to crack a probably-nonexistent nut.

Well, if you read the foundation postings on this subject, the nut does
exist. I still think that we are using the right sized wrench.

Later,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: Ian Jackson <[email-masked]>
Date: Sun, 25 Aug 96 16:56 BST

...
> done so. You declared the needlessness but gave no explanation of why this

Suppose that I were to declare that it is necessary for dpkg to be
able to read mail.  How would you refute my declaration of this
necessity ?  You can't.  Instead, you would ask me to justify this
assertion.

When the question is being discussed as to whether something is
necessary or not the burden of proof must fall on those who claim that
it is.  By default - in the absence of any reason not to think so -
a thing should be assumed not to be necessary.

> are neither constructive, nor informative.

I have read all of the discussion.  Just because I'm a week behind on
my email doesn't mean I'm not reading it.

However, since you seemed so insistent, I went back and had a look at
what arguments people might have presented.

I found a rather limited amount of discussion.  It did not appear to
me to have reached a definite conclusion.  The virtual package got
added by the maintainer of the list because noone objected in time.

The only one I could find was based on the idea that in order for it
to be safe to remove the `Essential' flag from `ae' it would be
necessary to use the dependency mechanism to stop people from
deinstalling it before they install another editor.

This didn't seem to be stated explicitly in this form, but it was
clear that people were seeing the idea of an `editor' virtual package
as an alternative to marking `ae' essential.

I don't see that this is a true case of alternative solutions to a
problem: I don't think there is a problem, and I think that it would
be just fine for `ae' not to be essential and for nothing to depend
on it.

Ian.

---

From: Dale Scheetz <[email-masked]>
Date: Mon, 26 Aug 1996 09:11:47 -0400 (EDT)

> be just fine for `ae' not to be essential and for nothing to depend
Thank you for speaking to the issues brought out by the previous
discussions.
I feel the need to make my position clear here. I have no "axe" to grind
here on this issue. My concerns are only that the issue be resolved
correctly. Part of my concerns stem from the past history of ae. I have
only recently taken over the maintainance of this package. When I got it,
the essential field had been declaired a bug, but the discussion of that
bug seemed to indicate that removal of the essential flag was not a
sufficient solution. In addition, I am concerned by the fact that this
field was only added to the package a couple of revisions ago, and now
needs to be removed. 
I don't see any difference, in principle, between an editor and a
mail-delivery-agent. They are both programs that deliver specific
functionality. The only differnce I can see is that an editor may not be
viewed as being as critical to system operations as the other, and Ian has
pointed out that users are likely to be more aware of their needs for an
editor than they are for other dependant programs. I am pretty sure that
we have users who are not this aware, but that is not the basis for my
feelings here. 
Ae is in the base package because it was deemed necessary to have an
editor in the system, and ae was small enough to fit. It is this necessity
that is driving the editor virtual package dependance as the proposed
solution. If it is not necessary for the system to contain an editor, then
why is one in the base system? If it is necessary for an editor to be on
the system, it seems desirable to provide protections from the inadvertant
removal of all editors. If there is a better way to insure the existance
of an editor on the system, I would be happy to hear it.
In addition, it is not clear to me that being unnecessary is the same as
undesirable. I can be convinced (no, really!) of either position at this
point. I just need a little more 'splaining.

Thanks,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: Ian Jackson <[email-masked]>
Date: Tue, 27 Aug 96 14:14 BST

Dale Scheetz writes ("Re: New virtual package names. "):
>... Part of my concerns stem from the past history of ae. I have

The fact that the field was added was a mistake, and it was noticed
and reported as a bug (several times, in fact).  It is not surprising
that once a mistake is made people ask for it to be unmade again.

I didn't see anything in that discussion to think that the removal of
the essential flag wasn't a full solution.  I saw several people with
the `hammer and nail' problem: `we have dependencies so we must use
them here'.

> we have users who are not this aware, but that is not the basis for my

If we have users who are not aware of this then they will not be
satisfied by `vi' or `ed' either - and these programs will have to
satisfy the dependency.  We can't solve this problem with the
dependency mechanism.

> why is one in the base system?

The base system is provided as a tool for installing the rest of the
packages, and is supposed to be a sensible default.

Both the essential flag and the dependency mechanism actually
_prevent_ the user from doing something, and we should only do this if
we really mean it.

>... If it is necessary for an editor to be on

What terrible thing do you think will happen if the user removes all
their editors ?  They'll sit there wanting to edit a file and think
  Damn, I can't figure out why I can't edit this file.  I just sit
  here blankly and wonder how I used to edit files.
?

> point. I just need a little more 'splaining.

For it to be right for us to do this there has to be a good reason in
favour of it.  It is not sufficient for it merely to be neutral.

In any case, it isn't neutral: it is a lot of work, and while the work
is done silly things will happen like users being forced to install
particular editors to satisfy the dependency scheme.

Ian.

---

From: Lars Wirzenius <[email-masked]>
Date: Tue, 27 Aug 1996 18:30:58 +0300

>   here blankly and wonder how I used to edit files.

Yes.

-- 
Please read <http://www.iki.fi/liw/mail-to-lasu.html> before mailing me.
Please don't Cc: me when replying to my message on a mailing list.

PS. I'm not sure if we want to care about that level of stupidity, though.

---

From: Dale Scheetz <[email-masked]>
Date: Tue, 27 Aug 1996 15:46:14 -0400 (EDT)

> that once a mistake is made people ask for it to be unmade again.

Well, I'm pretty sure that Bill didn't just wake up one morning and say
"Wow! That essential field sure is neat! Let's put it in ae! My assumption
was that this was an attempt to keep ae in the system.

> the `hammer and nail' problem: `we have dependencies so we must use

I understand your perceptions of this, but I saw the discussion as trying
to find a better solution than essential (which obviously didn't work
right) to the problem of keeping an editor in the system.

> satisfy the dependency.  We can't solve this problem with the

I'm not sure I follow any of what you just said. If we can't solve the
problem with the dependency mechanism, how then?

>   here blankly and wonder how I used to edit files.
Cute.
No, I am concerned about programs that might use $EDITOR as the means to
providing an editor. Pine, for instance, can be configured to call an
editor under certain circumstances. If no editor is available (due to
being removed) then, as we all know, pine will flash an error message for
all of 1/20th of a second and then stare at you. Emacs also has conditions
where it calls an outside editor, and I'm sure that there are others.
Problems of this type, caused by the lack of an editor will appear to be
bugs in other software. This is something to be avoided, in my estimation.

> favour of it.  It is not sufficient for it merely to be neutral.
See above...

> particular editors to satisfy the dependency scheme.
Well, I don't see a LOT of work. Packages that provide an editor will only
need to add it to the Provides: field. Until some base package (or some
other package) creates a Depends: for editor this causes no problems to
the system. That is, if the concept is integrated in the proper order, no
one will know it has happened. (Until they try to remove all editors)

Later,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: Rob Browning <[email-masked]>
Date: 27 Aug 1996 16:37:49 -0500

Dale Scheetz <[email-masked]> writes:

> (Until they try to remove all editors)

I don't want to cause trouble, but why don't we just completely
disallow the removal of ae.  It's harmless, and the entire package
only takes up 54K.  I can't see that it's worth spending another
second even thinking about.

Am I missing something?

--
Rob

---

From: Dale Scheetz <[email-masked]>
Date: Tue, 27 Aug 1996 19:35:41 -0400 (EDT)

> second even thinking about.
Well, this brings us full circle.
Rob, the declaration of ae as essential has been declared a bug. This kept
ae from being removed which caused some to complain. The current
discussion is an attempt to move beyond this. 
Ian's position is that it doesn't matter if ae and all other editors are
removed from the system. Yours is that it doesn't matter if ae can't be
removed. I hope that we can come to some middle ground here.

Thanks,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: Rob Browning <[email-masked]>
Date: 27 Aug 1996 19:12:52 -0500

Dale Scheetz <[email-masked]> writes:

> Rob, the declaration of ae as essential has been declared a
> bug. This kept ae from being removed which caused some to complain.

I cannot comprehend that anyone would care about one 54K package that
is arguably a special case (the most rudimentary editor).  If we were
doing stuff like this for 20 packages, fine, but we're not.

This issue is not worth worrying about.  The "right" solution (even if
we could agree on it), would require way more effort (i.e. any effort)
than the problem warrants.  Make "ae" Essential, and forget it.  We
have many more interesting and important things to worry about.

--
Rob

---

From: [email-masked] (Kai Henningsen)
Date: 29 Aug 1996 20:00:00 +0200

> bugs in other software. This is something to be avoided, in my estimation.

It seems there are several problems here:

1. Having an editor in the base system by default.

2. Keeping a system from becoming editorless.

3. Ensuring that packages needing an editor have one.

Now, (1) needs no special mechanism; just put ae into the base system and  
forget about it.

(2) is not really needed; an editor is not essential to package  
installation.

(3), on the other hand, would certainly benefit from an "editor" virtual  
package.

So, the important question boils down to "how important is (3)". What will  
it do for us to implement this?

As Dale said, it will keep some annoying problems from happening if  
someone deinstalls every editor.

Or will it?

Just what does, say, pine do, if we have all the editors installed, and  
$EDITOR is set to /this/doesnt/exist ?

Two possibilities:

a. It acts just like there is no editor. Oops, the virtual package doesn't  
help.

b. It falls back to a specific editor. Then we'd need that one, not any  
one, and again the virtual package doesn't help.

So, no joy here.

All we get is that, when all editors are removed, installing - say - pine  
will get us to install an editor.

Personally, I don't think that's worth it.

Of course, the update-alternatives thing with an "editor" program might do  
more for us, if we configure that as fallback. However, that is a lot more  
work.

My vote would be for dropping the idea (and the "essential" flag).

MfG Kai

---

From: Mark Eichin <[email-masked]>
Date: 30 Aug 1996 02:20:54 -0400

>  Emacs also has conditions
> where it calls an outside editor...

Interesting.  I'm aware of cases where it will call outside *viewers*
(mostly mime/web stuff) but I can't think of what outside editors it
would call.  Could you perhaps expand on this point?
					_Mark_

---

From: Dale Scheetz <[email-masked]>
Date: Fri, 30 Aug 1996 09:52:42 -0400 (EDT)

> would call.  Could you perhaps expand on this point?

I am a novice when it comes to emacs. My impression came from a bug report
on pine about pico leaving backup copies of email that are world readable.
It turned out that the emacs mail handler was calling pico with the
auto-backup enabled. This is what left me with that impression. (I was
sure that someone less ignorant than myself would surely correct me if I
was wrong)

Luck,

Dwarf

------------ If you don't see what you want, just ask --------------

---

From: Ian Jackson <[email-masked]>
Date: Sat, 31 Aug 96 17:32 BST

> was that this was an attempt to keep ae in the system.

I think that Bill was under the mistaken impression that every base
package should be marked essential.

...
> providing an editor.  [...]

As has been pointed out, the dependency scheme doesn't help at all
here.

Ian.