Code
po_update(verbose = TRUE, lazy = FALSE)
Output
Updating 'fr' R translation
Running system command msgmerge --update "./po/R-fr.po" --backup=off --previous "./po/R-test.pot" .
. done.
Updating 'ja' R translation
Running system command msgmerge --update "./po/R-ja.po" --backup=off --previous "./po/R-test.pot" .
. done.