gnus error: Invalid read syntax: ". in wrong context"

[Nomen Nescio]

Suddenly I can no longer read gwene.com.fatwallet.hotdeals using
gnus. It has been working for years, but now emacs fails with:

Retrieving newsgroup: nntp+news.gmane.org:gwene.com.fatwallet.hotdeals...
Fetching headers for nntp+news.gmane.org:gwene.com.fatwallet.hotdeals...
byte-code: Invalid read syntax: ". in wrong context"

It could be a gnus problem, or a corrupt gmane archive. Anyone else
having problems with that group?

The historical posts for this group are useless, so theoretically I
could just destroy the group and resubscribe, but then gnus would
automatically try to redownload the whole thing. Maybe I can mitigate
that.

[Lars Magne Ingebrigtsen]

Post by Nomen Nescio
Suddenly I can no longer read gwene.com.fatwallet.hotdeals using
Retrieving newsgroup: nntp+news.gmane.org:gwene.com.fatwallet.hotdeals...
Fetching headers for nntp+news.gmane.org:gwene.com.fatwallet.hotdeals...
byte-code: Invalid read syntax: ". in wrong context"

`(setq debug-on-error t)', repeat the bug and post the resulting
backtrace.