There are still a large number of python 2.4.3 installations, however the current bitbake fails to execute on this version of python. It's expected that bitbake will execute and display the error message: Sorry, python 2.6.0 or later is requried for this version of bitbake. Instead what happens is: File "/msp-lpggp12/mhatle/git/poky-contrib/bitbake//bin/bitbake", line 203 except Exception as e: ^ SyntaxError: invalid syntax It appears the 'as' clause of exception handing is not implemented in 2.4. Similar, if you change the 'as' to a ',', you get another error on line 207. The 'finally' clause of the try was not allowed until 2.5. So the exception handling and the finally clause may have to be re-evaluated in order to generate the proper error message.
The same problem also applies to python 2.5 installs (2.5.2 in Ubuntu Hardy for example).
bitbake in master (as of 2011-01-28) has fixed the root issue, and displays "RuntimeError: Sorry, python 2.6.0 or later is required for this version of bitbake" for both python 2.5.2 and 2.4.5. (see http://bugzilla.pokylinux.org/show_bug.cgi?id=629 ).
This is resolved in master so marking as resolved.