Backport

Copy a pull request to another branch once it is merged.

The backport action enables you to automatically create a backport of a merged pull request. When the conditions you specify are met, Mergify will create a new pull request to merge the changes into the specified base branch.

The backport action is extremely useful for maintaining older versions of your project. It helps automate the process of applying bug fixes or other changes from the main branch to other branches.

Note that in case of a conflict during the backport, Mergify will create a pull request with the conflict; you will have to resolve it manually. You can change this behaviour using the ignore_conflicts option.

Parameters

The backport action takes a list of branches to which the changes from the merged pull request will be backported. The branch names should be specified as strings.

Key name	Value type	Default
`assignees`	list of template
Users to assign the newly created pull request. As the type is a data type template, you could use, e.g., `{{author}}` to assign the pull request to its original author.
`body`	template	`\|- This is an automatic backport of pull request #{{number}} done by [Mergify](https://mergify.com). {{cherry_pick_error}}`
The pull request body.
`bot_account`	template
Mergify can impersonate a GitHub user to backport a pull request. If no `bot_account` is set, Mergify backports the pull request itself.
`branches`	list of branch names	`[]`
The list of branches the pull request should be copied to.
`ignore_conflicts`	`boolean`	`true`
Whether to create the pull requests even if they are conflicts when cherry-picking the commits.
`labels`	list of string
The list of labels to add to the created pull requests.
`label_conflicts`	`string`	`conflicts`
The label to add to the created pull request if it has conflicts and `ignore_conflicts` is set to `true`.
`regexes`	list of string
The list of regexes to find branches the pull request should be copied to.
`title`	template	`"{{ title }} (backport #{{ number }})"`
The pull request title.

As the title and body are templates, you can leverage any pull request attributes to use as content, e.g., {{author}}. You can also use this additional variable:

{{ destination_branch }}: the name of the destination branch.
{{ cherry_pick_error }}: the cherry pick error message if any (only available in body).

Examples

Using Labels to Backport

Below is an example of how to use the backport action:

pull_request_rules:
  - name: backport patches to the release branch and assign to original author
    conditions:
      - label=backport
    actions:
      backport:
        branches:
          - "release-1.0"
          - "release-1.1"
        assignees:
          - "{{ author }}"

Combining Automatic Merge

You can also combine the backport action with other actions like merge. This can be useful in scenarios where you want to automatically backport and merge pull requests that fulfill certain conditions.

Here’s an example:

pull_request_rules:
  - name: backport patches to the release branch
    conditions:
      - label=backport
    actions:
      backport:
        branches:
          - "release-1.0"
          - "release-1.1"

  - name: automatically merge backport if they pass tests
    conditions:
      - author=mergify[bot]
      - base~=^mergify/bp/
      - head~=^release-1.
      - check-success=continuous-integration
    actions:
      merge:
        method: merge

In this configuration, a pull request is backported when it has the label backport. Then, when the backport is created and passes the check named continuous-integration, it will be automatically merged.

Use Cases

Actions