Agent goes crazy with gmane.emacs.help

[Tassilo Horn]

Hi,

since a few days I cannot read gmane.emacs.help anymore.  When fetching
new messages, the *Group* buffer indicates that it has some new
articles, but when I hit RET on it I get:

20080306T100211.248> Retrieving newsgroup: nntp+Gmane:gmane.emacs.help...
20080306T100211.300> Fetching headers for nntp+Gmane:gmane.emacs.help...
20080306T100217.281> Fetching headers for nntp+Gmane:gmane.emacs.help...done
20080306T100217.370> Scoring...
20080306T100217.372> Scoring...done
20080306T100217.373> No articles in the group
20080306T100217.382> Exiting summary buffer and applying spam rules
20080306T100217.432> No unread news

When I enter it with `C-u 200 RET' it starts downloading 15MB and the
newest messages I get are from yesterday.

I tried expiring and regenerating the group's agent cache yesterday, but
that didn't help either.  The regeneration took more than 4 hours with
output like "Regenerating NOV entry for X..." counting from X > 50000 to
1.

While writing this mail I tried `gnus-agent-flush-group'.  Here are the
results after doing that:

  - C-u 10 RET => downloads 15 MB, Summary shows 10 msgs which are the
    newest when comparing with the gmane web interface
  - C-u 10 RET => No articles in the group
  - C-u 30 RET => downloads 15 MB, Summary shows 20 msgs
  - C-u 31 RET => downloads 15 MB, Summary shows 1 msg
  - C-u 30 RET => No articles in the group
  - C-u 32 RET => downloads 15 MB, Summary shows 1 msg
  - C-u 35 RET => downloads 15 MB, Summary shows 3 msgs
  - C-u 35 RET => downloads 15 MB, Summary shows 19 rather old msgs

The 15 MB it fetches are always between 15114 and 15120 KB.

Oh, now I noted that flushing should be followed by an expiry, but after
`M-x gnus-agent-flush-cache' on gmane.emacs.help followed by `M-x
gnus-agent-expire-group' it says:

20080306T104206.979> Expiring articles in nntp+Gmane:gmane.emacs.help
20080306T104207.071> gnus-agent-expire: Sorting entries... 
20080306T104207.320> gnus-agent-expire: Sorting entries... Done
20080306T104207.321> gnus-agent-expire: Merging entries... 
20080306T104207.360> gnus-agent-expire: Merging entries... Done
20080306T104209.298> gnus-agent-expire detected a missing NOV entry.  Run 
gnus-agent-regenerate-group to restore it.
20080306T104209.302> Expiry recovered 0 NOV entries, deleted 0 files, and freed 
0.000000 B.

I got such a "Missing NOV message" yesterday, but the regeneration
didn't fix it.  Today I don't have another 4 hours time...

So what can I do to debug the problem if you want more infos?  Or how do
I get gnus functional for that group again, maybe by deleting some stuff
from ~/News/agent/?

Bye,
Tassilo