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A zc.buildout extension to ease the development of large projects with lots of packages.



Let Mr. Developer help you win the everlasting buildout battle!

(Remixed by Matt Hamilton, original from

mr.developer is a zc.buildout extension that makes it easy to work with buildouts containing lots of packages, of which you only want to develop some. The basic idea comes from Wichert Akkerman's plonenext effort.


Add mr.developer to the extensions entry in your [buildout] section:

extensions = mr.developer

This enables additional [buildout] options:

This specifies the name of a section which lists the repository information for your packages. Defaults to sources.
This specifies the default directory where your development packages will be placed. Defaults to src.
This specifies the names of packages which should be checked out during buildout. Packages already checked out are skipped. You can use * as a wildcard for all packages in sources.
This defaults to false. If it's true, then all packages specified by auto-checkout and currently in develop mode are updated during each buildout run. If set to force, then packages are updated even when they are dirty instead of asking interactively.
This defaults to always. If it's always, then submodules present in each package in develompent will be registered and updated on checkout and new ones on updates via the develop command. If you don't want to initialize any submodule, set value to never. If you set the value to checkout, code inside submodules will be pulled only the first time, so the develop up command will leave the submodule empty. Note that update only initializes new submodules, it doesn't pull newest code from original submodule repo.
This defaults to false. If it's true, invalid server certificates are accepted without asking (for subversion repositories).
This sets the number of threads used for parallel checkouts. See Lockups during checkouts and updates why you might need this.

The format of entries in the [sources] section is:

name = kind url [key=value ...]

Where individual parts are:

The package name.
The kind of repository. Currently supported are svn, hg, git, bzr, darcs, cvs, or fs.
The location of the repository. This value is specific to the version control system used.
You can add options for each individual package with this. No whitespace is allowed in key, value, and around the equal sign. For a description of the options see below.

The per-package options are:

Common options

The path option allows you to set the base directory where the package will be checked out. The name of the package will be appended to the base path. If path is not set, sources-dir is used.

With full-path you can set the directory where the package will be checked out. This is the actual destination, nothing will be added.

The update option allows you to specify whether a package will be updated during buildout or not. If it's true, then it will always be updated. If it's false, then it will never be updated, even if the global always-checkout option is set.

The egg option makes it possible to manage packages which are not eggs with egg=false. All commands like update work as expected, but the package isn't added to the develop buildout option and the activate and deactivate commands skip the package.

The newest_tag option allows you to checkout/update to the newest tag. Possible values of the option are "true" and "false". The newest_tag_prefix option allows you to limit the selection of tags to those which start with the prefix. These two options currently only work for cvs and hg.


The url is one of the urls supported by subversion.

You can specify a url with a revision pin, like

You can also set the rev or revision option, which is either a pin like with rev=123 or a minimum revision like rev=>123 or rev=>=123. When you set a minimum revision, the repository is updated when the current revision is lower.


The branch option allows you to use a specific branch instead of master.

The rev option allows you to use a specific revision (usually a tag) instead of the HEAD.

The pushurl options allows you to explicitly separate push url from pull url, configured by git config.

The submodules option allows you to initialize existing submodules. Default value is controled by the buildout option update-git-submodules. Possible values are the same described before in update-git-submodules option,

Note that the branch and rev option are mutually exclusive.


The branch option allows you to use a specific branch instead of default.

The rev option allows you to force a specific revision (hash, tag, branch) to be checked out after buildout

Currently no additional options.
Currently no additional options.

The cvs_root option can be used to override the setting of the $CVSROOT environment variable. The tag option forces checkout/update of the given tag instead of CVS HEAD.

The tag_file option defines from which file tags will be read (in case of using newest_tag). Default value is "".


This allows you to add packages on the filesystem without a version control system, or with an unsupported one. You can activate and deactivate packages, but you don't get status info and can't update etc.

The url needs to be the same as the name of the package.

Here's an example of how your buildout.cfg may look like:

extensions = mr.developer
auto-checkout = my.package

my.package = svn update=true
some.other.package = git git://

When you run buildout, the script bin/develop is created in your buildout directory. With this script you can perform various actions on packages, like checking out their source code, without the need to know where the repositories are located.

For help on what the script can do, run bin/develop help.

If you checked out the source code of a package, you must run buildout again. The new package will then be marked as a development egg and have its version pin cleared (if any). You can control the list of development eggs explicitely with the activate and deactivate commands.

Any source where the path is a symlink is skipped during updates, as it is assumed, that the developer handles it manually. It is basically treated like a filesystem source.


You can add options to your global ~/.buildout/mr.developer.cfg or local .mr.developer-options.cfg in your buildout. Don't ever edit .mr.developer.cfg in your buildout though, it's generated automatically.

In the [mr.developer] section you have the following options.

This sets the number of threads used for parallel checkouts. See Lockups during checkouts and updates why you might need this.

In the [rewrites] section you can setup rewrite rules for sources. This is useful if you want to provide a buildout with sources to repositories which have different URLs for repositories which are read only for anonymous users. In that case developers can add a URL rewrite which automatically changes the URL to a writable repository.

The rewrite rules can have multiple operators:

Matches the exact string. Useful to only operated on sources of a certain kind and similar things. This doesn't rewrite anything, but limits the rule.
Matches with a regular expression. This doesn't rewrite anything, but limits the rule.
This runs a regular expression substitution. The substitute is read from the next line. You can use groups in the expression and the backslash syntax in the substitute. See re.sub documentation.

The following are useful examples:


plone_svn =
  url ~ ^

github =
  url ~ ^
  kind = git

my_mrdeveloper_fork =
  url ~ fschulze(/mr.developer.git)

my_mrdeveloper_fork_alternate =
  url ~= fschulze/mr.developer.git
  url ~ fschulze/


Dirty SVN

You get an error like:

ERROR: Can't switch package 'foo' to '' because it's dirty.

If you have not modified the package files under src/foo, then you can check what's going on with status -v. One common cause is a *.egg-info folder which gets generated every time you run buildout and this shows up as an untracked item in svn status.

You should add .egg-info to your global Subversion ignores in ~/.subversion/config, like this:

global-ignores = *.o *.lo *.la *.al .libs *.so *.so.[0-9]* *.a *.pyc *.pyo *.rej *~ #*# .#* .*.swp .DS_Store *.egg-info

HTTPS Certificates

The best way to handle https certificates at the moment, is to accept them permanently when checking out the source manually.

Mercurial reports mismatching URL

This happens if you use lp:// URLs from launchpad. The problem is, that hg reports the actual URL, not the lp shortcut.

Lockups during checkouts and updates

Especially on multicore machines, there is an issue that you can get lockups because of the parallel checkouts. You can configure the number of threads used for this in .mr.developer.cfg in the buildout root of your project or globally in ~/.buildout/mr.developer.cfg through the threads option in the [mr.developer] section or in your buildout in the buildout section with the mr.developer-threads option. Setting it to 1 should fix these issues, but this disables parallel checkouts and makes the process a bit slower.

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