rosmsg md5 Cannot locate message

edit

On a fresh install of Fuerte on Oneiric (desktop-full installed from binary packages) the command rosmsg md5 does not appear to work:

$ rosmsg md5 std_msgs/String 
Cannot locate [std_msgs/String]

while rosmsg show works as expected:

$ rosmsg show std_msgs/String
string data

Any suggestion about what might be causing the problem or on how to investigate the issue further is much appreciated.

Filed as ticket #3961