The 'select' method of Net::IMAP in Ruby 1.8.5 works fine with older Cyrus IMAP servers but is failing with the latest
Cyrus test release (2.3.7). There seems to be a problem parsing the NOMODSEQ line.

The code

  require 'net/imap'
  Net::IMAP.debug = true

  # ...

  imap = Net::IMAP.new(server)
  imap.login(user, password)
  imap.select('INBOX')

produces:

S: * OK [CAPABILITY IMAP4 IMAP4rev1 LITERAL+ ID AUTH=PLAIN SASL-IR] imap.example.com Cyrus IMAP4 v2.3.7 server ready
C: RUBY0001 LOGIN usernamehere passwordhere
S: RUBY0001 OK [CAPABILITY IMAP4 IMAP4rev1 LITERAL+ ID LOGINDISABLED ACL RIGHTS=kxte QUOTA MAILBOX-REFERRALS NAMESPACE
UIDPLUS NO_ATOMIC_RENAME UNSELECT CHILDREN MULTIAPPEND BINARY SORT SORT=MODSEQ THREAD=ORDEREDSUBJECT THREAD=REFERENCES
ANNOTATEMORE CATENATE CONDSTORE IDLE LISTEXT LIST-SUBSCRIBED X-NETSCAPE URLAUTH] User logged in
C: RUBY0002 NOOP
S: RUBY0002 OK Completed
C: RUBY0003 SELECT INBOX
S: * FLAGS (\Answered \Flagged \Draft \Deleted \Seen)
S: * OK [PERMANENTFLAGS (\Answered \Flagged \Draft \Deleted \Seen \*)]
S: * 0 EXISTS
S: * 0 RECENT
S: * OK [UIDVALIDITY 1165577702]
S: * OK [UIDNEXT 1]
S: * OK [NOMODSEQ] Sorry, modsequences have not been enabled on this mailbox
@str: "* OK [NOMODSEQ] Sorry, modsequences have not been enabled on this mailbox\r\n"
@pos: 15
@lex_state: EXPR_BEG
@token.symbol: RBRA
@token.value: "]"
/usr/lib/ruby/1.8/net/imap.rb:3104:in `parse_error': unexpected token RBRA (expected SPACE)
(Net::IMAP::ResponseParseError)
        from /usr/lib/ruby/1.8/net/imap.rb:2956:in `match'
        from /usr/lib/ruby/1.8/net/imap.rb:2747:in `resp_text_code'
        from /usr/lib/ruby/1.8/net/imap.rb:2723:in `resp_text'
        from /usr/lib/ruby/1.8/net/imap.rb:1994:in `response_cond'
        from /usr/lib/ruby/1.8/net/imap.rb:1954:in `response_untagged'
        from /usr/lib/ruby/1.8/net/imap.rb:1930:in `response'
        from /usr/lib/ruby/1.8/net/imap.rb:1856:in `parse'
        from /usr/lib/ruby/1.8/net/imap.rb:996:in `get_response'
        from /usr/lib/ruby/1.8/net/imap.rb:925:in `receive_responses'
        from /usr/lib/ruby/1.8/net/imap.rb:918:in `initialize'
        from /usr/lib/ruby/1.8/net/imap.rb:917:in `initialize'
        from ./test.rb:10

Date: 2007-02-19 10:29
Sender: Brian Chapados

Here is a patch to recognize and ignore the [NOMODSEQ] response.
This is probably not the proper way to handle this, but it will
allow Net::IMAP to function with these Cyrus IMAP servers:

Here is a pastie link in case the text below doesn't work
http://pastie.caboo.se/41345

--- imap.rb     2007-02-19 02:20:05.000000000 -0800
+++ imap-patched.rb     2007-02-19 02:22:00.000000000 -0800
@@ -2743,6 +2743,10 @@
         when /\A(?:UIDVALIDITY|UIDNEXT|UNSEEN)\z/n
           match(T_SPACE)
           result = ResponseCode.new(name, number)
+        when /\A(?:NOMODSEQ)\z/n
+          # recognize and ignore Cyrus IMAP 2.3.7+ NOMODSEQ
response
+          # reference: http://rubyforge.org/tracker/?func=detail
&atid=1698&aid=7233&group_id=426
+          result = ResponseCode.new(name, nil)
         else
           match(T_SPACE)
           @lex_state = EXPR_CTEXT