Pardon, obviously, the command and output should look like this (build dir brings duplicities):

$ grep -FRn .message . | grep -Fv -e .git/hooks -e ./build | sed -e 's/: \+/:  /g'
./luci/lib/async_helpers.py:38:  return { 'errors':  [ _('Unable to connect to host "%s":  %s') % (host, e.message) ] }
./luci/lib/ricci_communicator.py:58:  if e.message:
./luci/lib/ricci_communicator.py:60:  % (self.__hostname, self.__port, e.message)
./luci/lib/ricci_communicator.py:206:  % (self.__hostname, self.__port, e.message)
./luci/lib/ricci_communicator.py:241:  % (self.__hostname, self.__port, e.message)
./luci/lib/ricci_communicator.py:389:  if e.message:
./luci/lib/ricci_communicator.py:391:  % (self.__hostname, self.__port, e.message)
./luci/lib/ricci_communicator.py:429:  if e.message:
./luci/lib/ricci_communicator.py:431:  % (self.__hostname, self.__port, e.message)

This issue has been proposed when we are only considering blocker
issues in the current Red Hat Enterprise Linux release. It has
been denied for the current Red Hat Enterprise Linux release.

** If you would still like this issue considered for the current
release, ask your support representative to file as a blocker on
your behalf. Otherwise ask that it be considered for the next
Red Hat Enterprise Linux release. **

This issue has been proposed when we are only considering blocker
issues in the current Red Hat Enterprise Linux release. It has
been denied for the current Red Hat Enterprise Linux release.

** If you would still like this issue considered for the current
release, ask your support representative to file as a blocker on
your behalf. Otherwise ask that it be considered for the next
Red Hat Enterprise Linux release. **

Is there an error message that should replace this behavior?  I don't know which way the API changed and how luci should change, so I'm unsure what behavior to look for as an improvement.

(In reply to comment #5)
> Is there an error message that should replace this behavior?  I don't know
> which way the API changed and how luci should change, so I'm unsure what
> behavior to look for as an improvement.    

One of the ways how to reproduce it:
1. in Luci at the "Manage Clusters" section, select "Add" to open "Add an Existing Cluster"
2. fill "Node Hostname" field with not-existing hostname, fill the password and click "Connect"
3. in the log (e.g. console if you run luci in foreground), block of messages like this will appear (and at the same time the user is correctly informed that the connection cannot be established in the GUI) -- among them there is also that deprecation warning:

---snip---
../luci/lib/ricci_communicator.py:58: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  if e.message:
15:27:29,270 ERROR [luci.lib.ricci_communicator] Unable to establish an SSL connection to not.existing.cluster:11111: Name or service not known
Traceback (most recent call last):
  File "../luci/lib/ricci_communicator.py", line 42, in __init__
    0, socket.AI_PASSIVE):
gaierror: [Errno -2] Name or service not known
../luci/lib/async_helpers.py:38: DeprecationWarning: BaseException.message has been deprecated as of Python 2.6
  return { 'errors': [ _('Unable to connect to host "%s": %s') % (host, e.message) ] }
---snip---

Fixing this bug means removing that deprecation warning ~ making step for Luci to be compatible with Python 2.7.

This should be fixed in http://git.fedorahosted.org/git/?p=luci.git;a=commit;h=5efb11dae9a80b94ed9283b8fbe0b1c53af7166d

An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2011-0655.html