I'm a big fan of tools that encourage and/or enforce the following of best practices and that help people become more productive.
One of the tools that Firefox developers interact with nearly daily is Mercurial. As I've observed from coworkers and from community contributors, many don't have Mercurial configured for optimal development. For first-time contributors, this can manifest in patch rejection - an experience that can be embarassing and demotivating. This is frustrating to me because most issues are easily identifiable and correctable. And, when addressed, everyone wins.
Anyway, I'm pleased to announce that there is now a configuration wizard in the Firefox source tree to help with configuring Mercurial. To run it, just type:
Currently, it's aimed for first-time contributors. So, it's missing things that more seasoned developers rely on. But you need to start somewhere, right?
Currently, the tool isn't advertised anywhere other than mach help. Please run it and report issues in bug 794580 or file a new report. Once things have baked in, I'd like to add some kind of notification/tips system to mach where it will encourage you to do things like automatically run mach mercurial-setup. Until then, I recommend trying to remember to run mach mercurial-setup every few weeks to ensure your Mercurial environment is up to date and properly configured.
I'd like to thank Nick Alexander for sharing my enthusiasm for helping contributors and for taking the time to review this work.