Xcode project files use iOS Legacy Build System which is not supported in Xcode 13

The WorkspaceSettings.xcsettings file is generated with the following entry

<key>BuildSystemType</key>
<string>Original</string>

This causes the warning in [Link Removed] which has was closed by suppressing the warning, but Xcode 13 beta 4 no longer seems to allow the legacy build system.

Radar

rdar://problem/78763419

1. Download Xcode 13 beta 4 from developer.apple.com/downloads
2. Rename it to be Xcode_13_beta_4 and move it to Applications
3. open a terminal and run sudo xcode-select -s /Applications/Xcode_13_beta_4.app/Contents/Developer
4. Attempt to build UE4

A Legacy Build System error will occur.

Note to change back to the regular Xcode in Applications, run the command sudo xcode-select -s /Applications/Xcode.app/Contents/Developer