branchName not expanded in onboarding PR footer

[amezin]

What would you like help with?

I think I found a bug

How are you running Renovate?

Self-hosted

If you're self-hosting Renovate, tell us which platform (GitHub, GitLab, etc) and which version of Renovate.

Bitbucket Server, Docker image ghcr.io/renovatebot/renovate:37.320.1-full

Please tell us more about your question or problem

I have the following prFooter in config.js:

const parambuildUrl = new URL('../parambuild/', process.env.BUILD_URL).toString();
const triggerUrl = `${parambuildUrl}?RENOVATE_REPOSITORIES={{{encodeURIComponent repository}}}`;
const rebaseUrl = `${triggerUrl}&RENOVATE_CHECKED_BRANCHES={{{encodeURIComponent branchName}}}`;

module.exports = {
    prFooter: [
        `:arrow_double_up: [Run Renovate for the repository again](${triggerUrl})`,
        '',
        `:repeat: [Force update/rebase of this pull request](${rebaseUrl})`,
        '',
        `:information_source: [Logs](${logsUrl})`,
    ].join('\n')

For "regular" PRs, branchName is correctly expanded - i.e. "Force update/rebase of this pull request" link ends with RENOVATE_CHECKED_BRANCHES=branch-name.

For onboarding PR, it ends with &RENOVATE_CHECKED_BRANCHES=%7B%7B%7BbranchPrefix%7D%7D%7D%7B%7B%7BadditionalBranchPrefix%7D%7D%7D%7B%7B%7BbranchTopic%7D%7D%7D ({{{branchPrefix}}}{{{additionalBranchPrefix}}}{{{branchTopic}}} if un-url-escaped).

Logs (if relevant)

No response

[rarkins]

Please create a simpler example to reproduce

[github-actions[bot]]

Hi there,

Get your discussion fixed faster by creating a minimal reproduction. This means a repository dedicated to reproducing this issue with the minimal dependencies and config possible.

Before we start working on your issue we need to know exactly what's causing the current behavior. A minimal reproduction helps us with this. Discussions without reproductions are less likely to be converted to Issues.

To get started, please read our guide on creating a minimal reproduction.

Good luck,

The Renovate team