[pypy-dev] Mercurial workflow
jacob at openend.se
Tue Dec 14 18:04:06 CET 2010
now that the switch to Mercurial has happened, people are discovering that
their Subversion workflow habits don't quite work. This is because Mercurial
has a distributed philosophy, inlike svn which has the concept of the holy
central server where all operations take place.
In Mercurial, you do all the important operations in your local repository. If
you have a central node (which is not strictly necessary), you just push ready
made change sets to it. Any conflict resolving has already been done on your
This means that it is very convenient to have at least 2 repositories locally
(this takes hadly any extra space, since unchanged files are hard linked to be
the same file in each repository).
You keep one repository as a staging area to which you pull changes from the
central server (or other peoples repositories) and to which you pull changes
from your other local repositories. It is here you resolve any merge conflicts
and it is from here you do pushes of new versions to the central pypy server
For every idea you have, you clone your repository and do the work for the
idea in the clone. If you need to collaborate with someone else you
synchronize your repo with their repo without going through the central
server. Branching is a concept that is separated from the repository clones
and it is just as good an idea to make branches for new features as it was in
When you work on an idea you should keep in mind that it is an extremely fast
operation to commit your work. You can do it for a number of various reasons -
whenever you have made a set of changes that you feel belong together, if your
machine is flakey and you want to have a backup copy somewhere else or if you
want to continue the work on a different machine. I sometimes program in bed,
and it is very simple to do a pull from my workstation to my laptop.
The new workflow will make the detailed changes less visible to others, since
you commit work to the central server in fewer and bigger chunks. This means
that there will be fewer "oops, I misspelled this" and more of a higher level
view of what is being developed.
I hope this helps getting your minds around how to work with Mercurial. I hope
you will discover that the way it is different from svn will improve your work
environment and your work habits. It has done so for me.
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