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Git Guide

This guide will help you to set up your environment to be able to work on the Dancer2's repository.


This guide has been written to help anyone interested in contributing to the development of Dancer2.

First of all - thank you for your interest in the project! It's the community of helpful contributors who've helped Dancer grow phenomenally. Without the community we wouldn't be where we are today!

Please read this guide before contributing to Dancer2, to avoid wasted effort and maximizing the chances of your contributions being used.

There are many ways to contribute to the project. Dancer2 is a young yet active project and any kind of help is very much appreciated!


We value documentation very much, but it's difficult to keep it up-to-date. If you find a typo or an error in the documentation please do let us know - ideally by submitting a patch (pull request) with your fix or suggestion (see Patch Submission).


You can write extensions (plugins) for Dancer2 extending core functionality or contribute to Dancer2's core code, see Patch Submission below.

General Development Guidelines

This section lists high-level recommendations for developing Dancer2, for more detailed guidelines, see Coding Guidelines below.

Quality Assurance

Dancer2 should be able to install for all Perl versions since 5.8, on any platform for which Perl exists. We focus mainly on GNU/Linux (any distribution), *BSD and Windows (native and Cygwin).

We should avoid regressions as much as possible and keep backwards compatibility in mind when refactoring. Stable releases should not break functionality and new releases should provide an upgrade path and upgrade tips such as warning the user about deprecated functionality.

Quality Supervision

We can measure our quality using the CPAN testers platform.

A good way to help the project is to find a failing build log on the CPAN testers.

If you find a failing test report, feel free to report it as a GitHub issue.

Reporting Bugs

We prefer to have all our bug reports on GitHub, in the issues section.

Please make sure the bug you're reporting does not yet exist. If in doubt please ask on IRC.

Environment and Patch Submission

Set up a development environment

If you want to submit a patch for Dancer2, you need git and very likely also Dist::Zilla. We also recommend perlbrew (see below) or, alternatively, App::Plenv) to test and develop Dancer2 on a recent version of Perl. We also suggest App::cpanminus to quickly and comfortably install Perl modules.

In the following sections we provide tips for the installation of some of these tools together with Dancer. Please also see the documentation that comes with these tools for more info.

Perlbrew tips (Optional)

Install perlbrew for example with

$ cpanm App::perlbrew

Check which Perls are available

$ perlbrew available

It should list the available Perl versions, like this (incomplete) list:


Now run the init command for perlbrew. The init command initializes and controls processes. The init command is run as the last step of any startup process.

$ perlbrew init

Then install a version inside perlbrew. We recommend you give a name to the installation (--as option), as well as compiling without the tests (--n option) to speed it up.

$ perlbrew install -n perl-5.14.4 --as dancer_development -j 3

Wait a while, and it should be done. Switch to your new Perl with:

$ perlbrew switch dancer_development

Now you are using the fresh Perl, you can check it with:

$ which perl

Install cpanm on your brewed version of Perl.

$ perlbrew install-cpanm

Install various dependencies (required)

Install Dist::Zilla

$ cpanm Dist::Zilla

Get Dancer2 sources

Get the Dancer sources from github (for a more complete git workflow see below):

Clone your fork to have a local copy using the following command:

 $ git clone git://

The Dancer2 sources come with a dist.ini. That's the configuration file for Dist::Zilla, so that it knows how to build Dancer2. Let's use dist.ini to install additional Dist::Zilla plugins which are not yet installed on your system (or Perl installation):

 $ dzil authordeps | cpanm -n

That should install a bunch of stuff. Now that Dist::Zilla is up and running, you should install the dependencies required by Dancer2:

 $ dzil listdeps | cpanm -n

When that is done, you're good to go! You can use dzil to build and test Dancer2:

 $ dzil build
 $ dzil test --no-author

Patch Submission (Github workflow)

The Dancer2 development team uses GitHub to collaborate. We greatly appreciate contributions submitted via GitHub, as it makes tracking these contributions and applying them much, much easier. This gives your contribution a much better chance of being integrated into Dancer2 quickly!

NOTE: All active development is performed in the master branch. Therefore, all your contribution work should be done in a fork of the master branch.

Here is the workflow for submitting a patch:

  1. Fork the repository: and click "Fork";

  2. Clone your fork to have a local copy using the following command:

    $ git clone git://
  3. As a contributor, you should always work on the master branch of your clone.

    $ git remote add upstream
    $ git fetch upstream

    This will create a local branch in your clone named master and that will track the official master branch. That way, if you have more or less commits than the upstream repo, you'll be immediately notified by git.

  4. You want to isolate all your commits in a topic branch, this will make the reviewing much easier for the core team and will allow you to continue working on your clone without worrying about different commits mixing together.

    To do that, first create a local branch to build your pull request:

    # you should be in master here
    $ git checkout -b pr/$name

    Now you have created a local branch named pr/$name where $name is the name you want (it should describe the purpose of the pull request you're preparing).

    In that branch, do all the commits you need (the more the better) and when done, push the branch to your fork:

    # ... commits ...
    git push origin pr/$name

    You are now ready to send a pull request.

  5. Send a pull request via the GitHub interface. Make sure your pull request is based on the pr/$name branch you've just pushed, so that it incorporates the appropriate commits only.

    It's also a good idea to summarize your work in a report sent to the users' mailing list (see below), in order to make sure the team is aware of it.

    You could also notify the core team on IRC, on, channel #dancer or via web client.

  6. When the core team reviews your pull request, it will either accept (and then merge into master) or refuse your request.

    If it's refused, try to understand the reasons explained by the team for the denial. Most of the time, communicating with the core team is enough to understand what the mistake was. Above all, please don't be offended.

    If your pull request is merged into master, then all you have to do is remove your local and remote pr/$name branch:

    $ git checkout master
    $ git branch -D pr/$name
    $ git push origin :pr/$name

    And then, of course, you need to sync your local devel branch with upstream:

    $ git pull upstream master
    $ git push origin master

    You're now ready to start working on a new pull request!