Candidate accepted, publication rejected for a case-variant of an existing package

I uploaded the candidate `hTags` https://hackage.haskell.org/package/hTags-0.1.5/candidate,
but when I try to `--publish` a clash with [htags](https://hackage.haskell.org/package/htags) is reported.

I suppose a simple check could prevent such blunders.