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Launchpad Help > Packaging > Daily builds > Recipes


A bzr-builder "recipe" is a description of the steps needed to construct a package from a set of Bazaar branches. Its format specifies:

Writing a recipe

Recipes have a simple format.

Note: you can find an uncomplicated example in the getting started guide.

They always start with a line similar to this:

# bzr-builder format 0.2 deb-version 1.0+{revno}

Let's take a look at this in more detail:

Specifying the branches

The next line of a recipe specifies which branch to base the package on:


This says that we will use the trunk of the bzr project in Launchpad. This could just as easily be any other branch in Launchpad, using the short format that you can find on any branch overview page.

Next, you can specify any number of other branches to include. There are two ways to include those branches additional branches:


Most often you'll use the "merge" command:

merge fix-build lp:~bzr/bzr/fix-build

Here fix-build is a unique short name that we'll use to refer to this branch throughout the recipe. The short name can be anything you like, so long as it is unique to this branch within this recipe.

lp:~bzr/bzr/fix-build is the location of the branch.

In this example, the branch fix-build fixes a problem in the trunk that prevents it from building. This branch could be anything: stand-alone packaging information, some other modification to the branch that's not yet present in the trunk and so on.


Nesting works in a similar way but has more scope:

nest pyfoo lp:pyfoo foo

The nest keyword puts the contents of one branch into a specific location in another branch, instead of merging it.

In this case, we are nesting the contents of lp:pyfoo in a new foo directory in the lp:bzr branch. Again, we've given the branch a short name, pyfoo, that we can use to refer to it throughout the recipe.

You can also act on the nested branch in the same way as you can the main branch: you can merge and nest other branches in your nested branch.

Here's how:

nest pyfoo lp:pyfoo foo
  merge branding lp:~bob/pyfoo/ubuntu-branding

Any lines that are indented by two spaces, and are directly below your nest line, will act on the nested branch. In this example, the ubuntu-branding branch will be merged into pyfoo before it is nested in your primary branch.

Packaging information

One of the branches that you include in your recipe must include packaging information in the debian directory. You can include this from another branch, that includes packaging information only, using a merge or a nest:

merge packaging lp:~bzr/bzr/packaging

What our recipe looks like

Adding up all the lines above, our full recipe would look like this:

# bzr-builder format 0.2 deb-version 1.0+{revno}
merge fix-build lp:~bzr/bzr/fix-build
nest pyfoo lp:pyfoo foo
  merge branding lp:~bob/pyfoo/ubuntu-branding
merge packaging lp:~bzr/bzr/packaging

Specifying revisions

Sometimes you want to specify a specific revision of a branch to use, rather than the tip.

You can do this by including a revision specifier at the end of any branch line. For example:

merge packaging lp:~bzr/bzr/packaging revno:2355

Similarly for the main branch:

lp:bzr revno:1234

Bazaar allows you to tag a certain revision with an easily memorable name. You can request a specific tagged revision like this:

lp:bzr tag:2.0

Here, the recipe would use the revision that has the tag "2.0".

Version numbers and substitution variables

In the first line of the recipe, we specified a version number for the package we want to build, using:

deb-version 1.0+{revno}

Rather than specify a fixed version number, we need it to increase every time the package is built. To allow for this, you can use a two substitution variables.




Replaced by the date and time (UTC) when the package was built.


Replaced by the revision number of the primary branch.

{revno:<branch id>}

Replaced by the revision number of the branch you specify, using the short name specified elsewhere in the recipe.


Replaced by the upstream portion of the version number taken from debian/changelog in the final tree. For example: if the version is 1.0-1, this would evaluate to 1.0.

The advantages of using {revno} and/or {time}:

You can use as many substitution variables as you like. For example:

  deb-version 1.0+{revno}-0ubuntu0+{revno:packaging}+{time}

Here the packaging in revno:packaging refers to the short name we gave the branch we're using for packaging.

This example would generate a package version something like:


Next steps

Let's look at bzr-builder in more detail.

< Daily builds getting started

bzr-builder in detail >

Packaging/DailyBuilds/Recipes/Draft (last edited 2011-03-23 12:18:07 by matthew.revell)