rake guides --> Missing template credits.erb.textile

Some days ago, after a regular 'git pull', 'rake guides' started to
fail with the following error message:

['Normal' guides compile fine.]
Generating credits
/usr/lib/ruby/gems/1.8/gems/actionpack-2.3.2/lib/action_view/paths.rb:
66:in `find_template': Missing template credits.erb.textile in view
path ./guides/rails_guides/../source (ActionView::MissingTemplate)

Of course, 'credits.erb.textile' _is_ located in 'guides/source/'.

How can I fix this?

Could you please update the version of your rack and try again ?

Thanks.

Thanks for the immediate help. Case closed.