Note that most of those are actually to consider for code repository overall, thus could be interesting for Git too.
abort: outstanding uncommitted changesFAQ/CommonProblems, Mercurial official wiki
abort: push creates new remote heads!Using Mercurial MDC
My notes on Tools gather what I know or want to know. Consequently they are not and will never be complete references. For this, official manuals and online communities provide much better answers.