You can check if a PO file is valid with the following command:

        msgfmt -c -o /dev/null <po file>
      

The following errors were found in singularity 's PO files:

gettext: singularity/i18n/lang_de_DE/knowledge.po: can't guess language
gettext: singularity/i18n/lang_de_DE/story.po: can't guess language
gettext: singularity/i18n/lang_es_AR/knowledge.po: can't guess language
gettext: singularity/i18n/lang_es_AR/story.po: can't guess language
gettext: singularity/i18n/lang_es_MX/knowledge.po: can't guess language
gettext: singularity/i18n/lang_es_MX/story.po: can't guess language
gettext: singularity/i18n/lang_fr_FR/knowledge.po: can't guess language
gettext: singularity/i18n/lang_fr_FR/story.po: can't guess language
gettext: singularity/i18n/lang_gd/knowledge.po: can't guess language
gettext: singularity/i18n/lang_gd/story.po: can't guess language
gettext: singularity/i18n/lang_it_IT/knowledge.po: can't guess language
gettext: singularity/i18n/lang_it_IT/story.po: can't guess language
gettext: singularity/i18n/lang_pt_BR/knowledge.po: can't guess language
gettext: singularity/i18n/lang_pt_BR/story.po: can't guess language
gettext: singularity/i18n/lang_ru_RU/knowledge.po: can't guess language
gettext: singularity/i18n/lang_ru_RU/story.po: can't guess language
gettext: singularity/i18n/lang_sv_SE/knowledge.po: can't guess language
gettext: singularity/i18n/lang_sv_SE/story.po: can't guess language
      

Please ask the translator (identified by the Last-Translator field in the PO file), the language team (identified by the Language-Team field) or debian-i18n for a fix.