Second hierarchy migration fails due to index name clash #128
Description
I use closure tree to create hierarchies for two models in my app. The first one succeeds, but the second one fails, due to the generated index name conflict ("anc_desc_idx" and "desc_idx") . Renaming these indices to be model specific ("tag_anc_desc_idx" and "tag_desc_idx", for instance) is a workaround.
Expected: The index name generated to include the model name to disambiguate indices across models.