$ rake updatepo                                                                
(in /home/fofo/prog/ruby/rails/ncsite/trunk/ncsite)
po/ncsite.pot
po/fr_FR/ncsite.po
. done.
Failed to merge with po/fr_FR/ncsite.po
New .pot was copied to tmp.pot~
rake aborted!
`/usr/local/bin/msgmerge' may not be found. 
Install GNU Gettext then set PATH or MSGMERGE_PATH correctly.

(See full trace by running task with --trace)
$ msgmerge
msgmerge: no input files given
Try `msgmerge --help' for more information.
$