PSA: Improvements to Uplift Requests in Lando

[Connor Sheehan]

Hey folks,

tl;dr: Lando uplift requests now support selecting multiple trains at once, run early merge conflict checks, and provide clearer feedback when something goes wrong.

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Yesterday we deployed an update to streamline the Lando uplift request workflow:

- Single submission for multiple trains: You can now select multiple uplift targets (e.g. `firefox-beta`, `firefox-release`) in one request and complete the uplift assessment form just once. Previously each separate train required visiting the page and creating a new submission to Lando.
- Early merge conflict feedback: Lando now runs background jobs to test whether your patch stack applies cleanly before creating uplift revisions. Previously these merge conflicts were only detected at landing time.
- Better error reporting: Uplift requests are only created if they already apply cleanly to the target uplift train. If patches don't apply, failure emails include guidance on how to proceed.

There will be more updates to the uplift workflow coming soon. If you want to share feedback, please join us in #uplift-pilot on Slack, or #Conduit on Matrix.
 
Cheers,  
Connor