cubicweb #503071 weird display with internationalizable [resolved]

I've redefined StringField with:

However I don't obtain an empty string for the first option as expected but this from gettext:

(u'MIME-Version: 1.0nContent-Type: text/plain; charset=UTF-8nContent-Transfer-Encoding: 8bitnGenerated-By: pygettext.py 1.5nPlural-Forms: nplurals=2; plural=(n > 1);n', '')
prioritynormal
typebug
done in3.5.6
load0.200
load left0.000
closed by#34fdb8fb49d1 [B] web: weird display with internationalizable (Closes: #503071)