Did so many changes in an app that you can't even count them and need to undo all of them? Lucky you, there is a way if you have any old build for the project.
We store bitrise.yml files for each and every build completed on Bitrise so that you can always check the config a given build was running with and use that if you need it later.
To check a build’s bitrise.yml you have to select an app and one of its builds.

Then click on BUILD’S BITRISE.YMLon the LOGS tab.

In a popup, you will see the bitrise.yml which was used for this particular build. The content will be loaded into the good old ace editor but you’ll not be able to edit it. This is for backup only.

If your current bitrise.yml file differs from the build’s bitrise.yml file you will see two ace editors in the popup: the build’s bitrise.yml on the left and the current bitrise.yml on the right. The differences between the two yml files will be highlighted with different colours.
The highlights mean:
- green - added content
- blue - changed content
- orange - deleted content

This makes it super easy to check your changes. And if you are not content with the updates you made, you can restore the YML to the build’s bitrise.yml right from the popup, just click on RESTORE button on the bottom.

Confirm and enjoy.
You have to confirm this action, because it overrides the bitrise.yml.

Happy building!