Quoting Andre Luis Lopes (andrelop@debian.org):

After updating the translation and checking it against msgfmt, it complained about plural form translations lacking "plural=EXPRESSION" attributes, as can be seen bellow :

ndrelop@foolish:~/i18n/shadow$ msgfmt -c -v -o /dev/null pt_BR.po pt_BR.po:112: message catalog has plural form translations... pt_BR.po:6: ...but header entry lacks a "plural=EXPRESSION" attribute pt_BR.po:112: message catalog has plural form translations... pt_BR.po:6: ...but header entry lacks a "nplurals=INTEGER" attribute 464 mensagens traduzidas. andrelop@foolish:~/i18n/shadow$

Do you know what should I do to quiet msgfmt ?

Anyway, the updated pt_BR.po file which generated the massage above is attached.

Hmmm ? I should have mentioned this to you, sorry.

There is now a use of plural forms. So you need adding this in the header:

Plural-Forms: nplurals=2; plural=n>1;

Which means pt_BR has two forms (singular and plural), the plural being used as soon as the number of objects is more than 1, the singular is used for 0 and 1.

http://www.gnu.org/software/gettext/manual/html_node/gettext_150.html for details

In the shadow *program* translation, all of you, translators, need to add the correct line for your language in the header. Please refer to the above URL for finding the exact line, which depends on your language.