How do you deal with incomplete commits?

[David Hurka]

> I ended up writing a local pre-commit hook, which has the advantage of
> triggering on the commit directly after "the problem commit", thus
> increasing the likelihood there is still a trivial way to sort
> things out.

It would probably be nice to have some post-checkout commit, with which you 
can spit you own WIP commit message in your face, right after you switch to 
your work branch.

There are update.sample and post-update.sample, but my git knowledge is 
missing in this point. What is “update”?

And now that we discovered that this is possible: I would like to have the 
pre-commit hook globally, that would fit my workflow nicely. How can I do 
that? My home directory is unfortunately not a git repository. ;)