UE4.26 and later comes with FASTBuild integration

[yhyu13]

Just let you guys know that UE4.26 and later comes with it own FB integration, with souce code modification under UnrealEngine\Engine\Extras\ThirdPartyNotUE\FASTBuild, and the FASTBuild.cs configuration files is also written by Epic under the UBT folder.

[ricekab]

Oh nice, thanks for sharing. The FASTBuild.cs file at the time of writing can be found in the repo under /Engine/Source/Programs/UnrealBuildTool/Executors/Experimental/FASTBuild.cs