So, you have working copy changes, do hg pull/update which conflicts with them. You're told:
use 'hg resolve' to retry unresolved file merges
So you edit the file to resolve conflicts, then run
hg resolve hg.txt
Right? No, because you get very strange output:
warning: conflicts during merge.
merging foo.txt failed!
And see that all your careful edits are blown away and file is back to conflicted state. Now you read man, to find out that you need to use -m option to mark file as resolved.
The question is: how can someone design such a UI that not only requires additional option for the most common operation, but also by default silently clobber users changes, which may be result of an hour or so of work? They say that git's interface is not that good (I used to think that too). Just look around.