Right now, if an unrecognized member is encountered during the references pass, it's silently ignored. For functions, this is the best we can do, since the unrecognized function could be a CSS function (or part of a post-processor). However, we should have enough context to error when unrecognized variables and mixins are encountered. This should prevent the migrator from improperly migrating a file that it doesn't have sufficient context for.
Right now, if an unrecognized member is encountered during the references pass, it's silently ignored. For functions, this is the best we can do, since the unrecognized function could be a CSS function (or part of a post-processor). However, we should have enough context to error when unrecognized variables and mixins are encountered. This should prevent the migrator from improperly migrating a file that it doesn't have sufficient context for.