GraphicsMagick Mercurial


The GraphicsMagick source code is now available via Mercurial. Previously GraphicsMagick source control was via CVS, but now the repository has been migrated to Mercurial. Mercurial is a convenient way for developers from around the country or world to download the GraphicsMagick source, fix bugs, or add new features. Due to the way Mercurial works, it may also be used to manage local changes to GraphicsMagick.

What is Mercurial?

Mercurial (also known as Hg due to the abbreviation for Mercury in the periodic table of the elements) is a modern source control system which provides anyone who clones a repository with a stand-alone local repository containing the full development history and the ability to select any version of the code. Since the local repository is fully-functional, you may use the same repository to manage your local changes to GraphicsMagick code and you may use the repository to share your changes with others.

Web Access

The GraphicsMagick repository at SourceForge web interface is available which may be used to interactively view the latest versions of files, or the changes to files, using your web browser. Please note that the SourceForge web interface to repositories is the worst that we have ever experienced and it is difficult to imagine how it could be worse. This was not the case when Mercurial was initially used at SourceForge and Mercurial's native web interface was offered. The user is advised to clone the whole repository and use Mercurial's own web interface, or a graphical tool like Tortoise Hg on their own machine to peruse the files and change history.

Cloning the Mercurial Repository

To get the tree and place it in a sub-directory of your current working directory, issue the command:

hg clone GM

Selecting a version of the code

By default the cloned directory is populated with files from the default (i.e. head) branch of the code.

If you require a specific release of GraphicsMagick (e.g. 1.3.9), you may select it like:

hg update -r GraphicsMagick-1_3_9

or if you require a specific branch of GraphicsMagick (e.g. 1.3), you may use:

hg update -r GraphicsMagick-1_3

or you may request the files which were current on a specific date:

hg update -d 2009-01-14


hg branches

to see the available branches, and:

hg tags

to see the available release tags.

Updating from the Mercurial Repository

To pull more changes from the repository, execute:

hg pull

and to make them visible in your files (via a merge), execute:

hg update

or just:

hg pull -u

The latter pulls down any updates into your local repository and automatically does a merge.

Mercurial Software

The best place to look for the latest version of Mercurial (Hg) is at the Mercurial web site. Most free operating systems (e.g. Linux, OpenSolaris, and *BSD) will offer a version of Mercurial as an installable package and it may already be installed on your system. We recommend use of TortoiseHg on Microsoft Windows systems since it provides a very nice graphical interface. TortoiseHg is also available on Linux and other systems.

Mercurial for GraphicsMagick Developers

Since Mercurial is a distributed revision control system, you may clone the GraphicsMagick repository and work for days or weeks (making your own local commits) before you deside to push some or all of your changes to the GraphicsMagick development repository. GraphicsMagick developers first commit changes to their own local respository, then they push their changes to the GraphicsMagick development repository at, later on (after testing and possible fixes) I will push the changes to the stable repository at SourceForge. Pushes to the stable repository at SourceForge should occur at least as often as source code snapshots are produced.

The repository hierarchy is as follows:

  1. Local
The developer makes any local changes and commits he likes in his own repository. It is best to commit often and whenever all the files have been updated to implement a coherent change or feature (including the ChangeLog file!) since Mercurial stores related changes as a changeset along with the change message you enter. When you push your repository, these changesets and messages are preserved.
  1. Unstable

The unstable development repository is available via ssh at "ssh://".

Where yourid is the Unix user ID on the GraphicsMagick server. The yourid@ part may left out if your client system uses the same user ID as on the GraphicsMagick server.

  1. Stable
The stable repository is available via http at "". Any changes in the unstable development repository are pushed to the stable repository (by the developer responsible for this role) once any necessary adjustments have been made, documentation files have been generated, and the software test suite has passed on at least one machine.

To build your local development repository (as quickly as possible), you may use these steps:

  1. Clone the stable respository at SourceForge:

    hg clone GM
  2. Adjust your local repository path default to use the unstable repository.

    Edit .hg/hgrc in your local repository so that it contains:

    default = ssh://

    where yourid is the Unix user ID on the GraphicsMagick server.

  3. Pull any additional pending updates from the unstable repository:

    hg pull -u

Please note that when ssh access is used, Mercurial uncompresses any data and sends it in uncompressed form. Mercurial expects that compression will be enabled in ssh when needed. One way to enable ssh compression is to put this in your local .hgrc:

ssh = ssh -C

but ssh also provides its own way to enable compression on a site-by-site basis (e.g. via .ssh/config). For example an entry in .ssh/config will enable use of compression:

  Compression yes

Email Notifications

An email notification is sent to the graphicsmagick-commit mailing list at SourceForge whenever a change is submitted to the development (unstable) repository. Subscribe to this list if you would like to be notified by email of changes when they occur.

Rsync The Repository

It is possible to use the rsync program to make a copy of the GraphicsMagick Mercurial repository. Using rsync might be faster for the initial repository checkout, but the copied repository might not be coherent if it was updated while the rsync was in progress. If there is any problem, just execute the same rsync command again without deleting any files and the remaining changes (updated files) will be transferred. To use rsync to copy the repository do:

mkdir -p GM
rsync -avPSz GM/

Rsync will not checkout a working set of files. To accomplish that do:

cd GM
hg update

Mercurial Topics

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