Sharing Mercurial Queues to Develop XPCOMGC

One of the development techniques we’re experimenting with for Mozilla2 is the use of Mercurial Queues (MQ). Queues are a way of maintaining a set of patches on top of a base repository.

There are a few features of MQ that have made it very useful:

MQ is ideal for doing large coding experiments such as XPCOMGC: it can keep track of manual rewriting and automatic patches separately; patches can be saved for review and merging upstream without delaying coding work; and the patch repository can be shared between the team doing the work.

The XPCOMGC patch repository is available publicly at The patches are against the ActionMonkey tree… please don’t expect much more than “it builds” yet… the browser won’t start yet, due to various unrooted objects, bad assumptions, and other undiagnosed problems.

Caution: To use MQ effectively, you must set the following settings in your ~/.hgrc:

[extensions] =
git = 1

You must turn on git-style patches, or bad things will happen if you try to add/remove/move files!

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