Currently, the import tool allows to convert the homepage of the media wiki in the homepage of the wiki. However, the homepage of media wiki is always considered to be the page with name Main_page, while this name can be, actually, internationalized in the configuration of the media wiki being imported (e.g. Accueil in french), and this name will appear in the export.
I implemented a fix for this issue in commit dde04cce12289fa17aa093f52e7395030833b6d0 , which works fine for my usecase: I extract the name of the homepage from the base url of the media wiki dump, the particle after the last slash, if any (if none, default english value is used). Thomas Mortagne, can you please validate this, and close the issue if it looks fine to you? (this is basically because I don't know how to make a pull request ).
Tests for this situation are included in the i18n tests committed in dbb840ccc8278e7f9c87c7b4a03a7c8f50a079d6 .