"Trying to require a method that doesn't exist"

"Trying to require a method that doesn't exist"

[Harry Putnam]

problem that produces this message: "Trying to require a method that
doesn't exit"
This is a recent Redhat Linux 5.1  install on a Toshiba laptop 4005CDS
(pentium II 266)

Running pgnus-0.64, currently.  Each time this problem has cropped up
I've tried going back to gnus-5.6.45 and a few in between, but once I
start getting this message gnus will not start.  Soon after pressing
"M-x gnus" comes the message.

With my poor understanding of gnus functioning the only way I have
gotten around it is to rename .newsrc.eld then let gnus generate
another one.  Add an nnml server and let it regenerate.   Doing it
this way looses track of read and unread in the newsgroups but also
looses the "group parameter" info on nnml groups.  Although the mail
is retained in tact, any special marks etc are lost.

This hasn't been to big a problem since I haven't run the laptop enough
to have much to lose.

However I'd like to know what is causing the problem.  I only saved
the most recent back-trace which is included below, but the others also
contained a line about a nnml group scan (group "Dan" below") each
time a different group.  It didn't seem to me that nnml scans should
be happening yet, but of course thats just a wild guess.

Back Trace (byte-code long-lines chopped but not changed):

Signaling: (error "Trying to require a method that doesn't exist")
  signal(error ("Trying to require a method that doesn't exist"))
  error("Trying to require a method that doesn't exist")
  gnus-server-opened((nil ""))
  gnus-activate-group("nnml:mail.Dan" scan)
  gnus-get-unread-articles(nil)
  gnus-setup-news(nil nil nil)
  byte-code("\b„\x0e

ˆÓ\x0e\x1a!ˆÔ ˆÕÖ!ˆ× ˆÇØ!ˆÐ‡" [dont-connect 
did-connect gnus-startup-file gnus-current-startup-file gnus-slave 
gnus-use-dribble-file gnus-group-quit gnus-run-hooks 
gnus-startup-hook gnus-make-newsrc-file gnus-dribble-read-file 
bbb-login add-hook gnus-summary-mode-hook gnus-grouplens-mode 
gnus-setup-news nil gnus-setup-news-hook gnus-start-draft-setup 
gnus-group-list-groups gnus-group-first-unread-group 
gnus-configure-windows group gnus-group-set-mode-line 
gnus-started-hook gnus-use-grouplens level] 4)
  gnus-1(nil nil nil)
  gnus(nil)
  call-interactively(gnus)
  execute-extended-command(nil)
* call-interactively(execute-extended-command)

Haven't been able to identify specific conditions that obtain when
this happens.

-- 
Harry Putnam <reader@newsguy.com>
Running Redhat Linux 5.1
.

Re: "Trying to require a method that doesn't exist"

[Mike McEwan]

Harry Putnam <reader@newsguy.com> writes:

> Signaling: (error "Trying to require a method that doesn't exist")
>   signal(error ("Trying to require a method that doesn't exist"))
>   error("Trying to require a method that doesn't exist")
>   gnus-server-opened((nil ""))

  Well isn't that the problem right there? `(nil "")'. There's no such
method as `nil' and hence `gnus-get-function' issues the message. That
should probably be `(nnml "")'. The select method for a group is held
in the group's info, which is in (guess :-)), .newsrc.eld. You'll
probably have to reset all your groups up again from scratch, or go
edit the affected group's infos with a `G E'. If that's not it -
what do your select-methods look like (parenthesis and all :-)).

-- 
Mike.

Re: "Trying to require a method that doesn't exist"

[Harry Putnam]

Mike McEwan <mike@lotusland.demon.co.uk> writes:

> Harry Putnam <reader@newsguy.com> writes:
> 
> > Signaling: (error "Trying to require a method that doesn't exist")
> >   signal(error ("Trying to require a method that doesn't exist"))
> >   error("Trying to require a method that doesn't exist")
> >   gnus-server-opened((nil ""))
> 
>   Well isn't that the problem right there? `(nil "")'. There's no such
> method as `nil' and hence `gnus-get-function' issues the message. That
> should probably be `(nnml "")'. The select method for a group is held
> in the group's info, which is in (guess :-)), .newsrc.eld. You'll
> probably have to reset all your groups up again from scratch, or go
> edit the affected group's infos with a `G E'. If that's not it -
> what do your select-methods look like (parenthesis and all :-)).

Thanks Mike,
The same thing happened again today.  Stopping all use of gnus.

Your clues led me to find an improper entry in .newsrc.eld in the
section that holds the Group Information.  Begins with:
"(setq gnus-newsrc-alist ......"

One of the nnml group entries looks like this:
("nnml:mail.Barb" 3 ((1 . 1)) ((reply 1)) "nnml:")

Where as others have the proper form like so:
("nnml:mail.misc" 3 ((1 . 53) (57 . 57)) ((reply 53)) (nnml ""))

Notice the last part with "nnml" is formatted differently.

I changed the Barb group to:
("nnml:mail.Barb" 3 ((1 . 1)) ((reply 1)) (nnml ""))
And Gnus will start again.

But still haven't figured out what I am doing to cause the improper
format to show up every few days.

Seems it may be related to Group parameter settings.
Looking back I see each time it has occured it has involved a group
where I have set  some Group Params.  Mostly just "gcc-self" and
"to-address"

I don't see anything obvious there.

At least now I know what  to look for, and how to edit it.

Anyone have an idea what might be the underlying cause?

-- 
Harry Putnam <reader@newsguy.com>
Running Redhat Linux 5.1

.

Re: "Trying to require a method that doesn't exist"

[Simon Josefsson]

Harry Putnam <reader@newsguy.com> writes:

> Your clues led me to find an improper entry in .newsrc.eld in the
> section that holds the Group Information.  Begins with:
> "(setq gnus-newsrc-alist ......"
> 
> One of the nnml group entries looks like this:
> ("nnml:mail.Barb" 3 ((1 . 1)) ((reply 1)) "nnml:")
> 
> Where as others have the proper form like so:
> ("nnml:mail.misc" 3 ((1 . 53) (57 . 57)) ((reply 53)) (nnml ""))
> 
> Notice the last part with "nnml" is formatted differently.

Since 0.52 pGnus tries to shorten select methods to a virtual server
name if the method is native or secondary -- this lets you change your
server variables in ~/.gnus without having to edit your ~/.newsrc.

That is, "nnml:" is really a valid method field in your ~/.newsrc.

I think that you no longer have `(nnml "")' in
`gnus-secondary-select-methods', is that true?

If this is the case, I think the error message is valid and you should
let Gnus know about a nnml-backend named "" and things should work (by
adding `(nnml "")' to `gnus-secondary-select-methods' or something to
that effect).

/s

Re: "Trying to require a method that doesn't exist"

[Harry Putnam]

Simon Josefsson <jas@pdc.kth.se> writes:

> Harry Putnam <reader@newsguy.com> writes:
> 
> > Your clues led me to find an improper entry in .newsrc.eld in the
> > section that holds the Group Information.  Begins with:
> > "(setq gnus-newsrc-alist ......"
> > 
> > One of the nnml group entries looks like this:
> > ("nnml:mail.Barb" 3 ((1 . 1)) ((reply 1)) "nnml:")
> > 
> > Where as others have the proper form like so:
> > ("nnml:mail.misc" 3 ((1 . 53) (57 . 57)) ((reply 53)) (nnml ""))
> > 
> > Notice the last part with "nnml" is formatted differently.
> 
> Since 0.52 pGnus tries to shorten select methods to a virtual server
> name if the method is native or secondary -- this lets you change your
> server variables in ~/.gnus without having to edit your ~/.newsrc.
> 
> That is, "nnml:" is really a valid method field in your ~/.newsrc.
> 
> I think that you no longer have `(nnml "")' in
> `gnus-secondary-select-methods', is that true?
> 
> If this is the case, I think the error message is valid and you should
> let Gnus know about a nnml-backend named "" and things should work (by
> adding `(nnml "")' to `gnus-secondary-select-methods' or something to
> that effect).

It may well be that you are on the right track, but the secondary and
primary select methods have remained unchanged for months.


grep "select" .gnus:
;   (setq gnus-select-method '(nntp "enews.newsguy.com"))
(setq gnus-secondary-select-methods '((nnml "")))

I'm just using the env settings for nntp server selection, hence the
comment.

As mentioned previously, each time the problem has come up (completely
blocking use of gnus) it has involved a group where group params have
been set.  Leading me to think it may be caused by my entering some
sloppy lisp in the group params.  The problem has been, how to get to
the group params with gnus not functioning.  I'm beginning to see a
little better how .newsrc.eld works, and at least know what to look
for, but still haven't been able to tell what caused the problem.  If
it comes up again, have you an idea how to better track the source of
the problem?


-- 
Harry Putnam <reader@newsguy.com>
Running Redhat Linux 5.1

.