Interacting with bors

Bors is the merge queue bot we use in the Ferrocene monorepo (and smaller adjacent repositories), as described in the qualification plan. This page explains how developers can interact with it.

Pull request comments

The primary way to interact with bors is by including “bors commands” in your pull request comments, on their own line. The following commands should be used:



bors merge

Approve the current PR and put it into the queue.

bors cancel

Remove the current PR from the queue and cancel the merge. Does not affect try builds.

bors try

Start a try build of the CI pipeline, without merging.

bors try-

Cancel the try build.

bors retry

Execute the previous command again.

bors p=NUMBER

Set the priority of the PR to NUMBER (must be an integer).

bors single on

Merge this PR without grouping it with other PRs.

bors single off

Merge this PR by grouping it with other PRs.

bors ping

Check whether bors is active.


The behavior of bors retry differs from the behavior of upstream’s bors implementation (called “homu”). As explained in the table above, the retry command re-executes the previous command, it doesn’t attempt to merge the PR again.

In practice, if you first type bors merge and then bors retry, bors will attempt to merge the PR again, and this is because it ends up executing bors merge twice. If instead you run bors merge, bors p=10 and then bors retry, the priority would be set twice.

Inspecting the queue

The bors queue can be inspected at (after selecting the repository you want to see). Note that the queue is only available to Ferrous Systems employees.