docusaurus build has no way to keep path-based locale switching in a single-locale build #12586

Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

The docusaurus build command automatically disables path-based locale switching for single-locale builds. Per code comments, this decision was made to more easily support domain-based locale switching. However, the CLI offers no way to override this behavior and keep path-based locale switching for single-locale builds, which means Docusaurus users cannot build locales in parallel if they want to keep path-based locale switching.

Reproducible demo

No response

Steps to reproduce

1. Create a Docusaurus site with multiple locales
2. Build the locales in parallel and then merge the builds

Expected behavior

It should be possible to build locales for a Docusaurus site in parallel and then merge them. The CLI should offer a way to turn off

Actual behavior

The CLI builds each locale to the root path, so builds cannot be easily merged, and the locale dropdown does not work correctly (selecting a different locale reloads the default locale page instead of switching to the selected locale).

Your environment

• Public source code:
• Public site URL:
• Docusaurus version used:
• Environment name and version (e.g. Chrome 89, Node.js 16.4):
• Operating system and version (e.g. Ubuntu 20.04.2 LTS):

Self-service

• I'd be willing to fix this bug myself.