Working setup for UE 4.21

I’ve spent the last couple weeks (on and off) getting FastBuild to work with UE 4.21. I’ve included my setup in the gist below, hopefully it’s useful to someone before 4.22 undoubtedly breaks something again.

This was testing with a complete clean & rebuild with a slightly modified version of UE 4.21 . I have not tested this configuration with any FastBuild caching.

An overview of the changes and additions:

• Created some extension methods for VCEnvironment to patch things that were removed or changed from 4.19 . Some of the solutions in here aren’t very clean and may require some retooling. I placed this under UnrealBuildTool\Platform\Windows\VCEnvironmentFastbuildExtensions.cs (See gist for code).
• Set bEnableUndefinedIdentifiedWarnings to false in UnrealBuildTool\Configuration\ModuleRules.cs. This was breaking compilation with Windows 10 SDK. (See gist for code).
• Added an action to support ActionType.BuildProject in FASTBuild.cs. This may not work for everything. I’ve only seen this action type used for copying files so that is what it does in the BFF file. FASTbuild.cs also modified to work with modified VCEnvironment.
• ActionGraph and BuildConfiguration required no changes compared to 4.19 .

View changes in code: https://gist.github.com/RiceKab/60d7dd434afaab295d1c21d2fe1981b0

[liamkf]

Hi there! We just haven’t run with caching recently, I don’t see why it couldn’t be working though… 😃

As far as Xbox distribution goes, https://github.com/fastbuild/fastbuild/issues/363 and https://github.com/fastbuild/fastbuild/issues/438 still remain in effect unfortunately…

[ttvd]

It does look like it will take significant amount of effort to get xb1 working with fastbuild due to /zw. PCH and the fact that some core modules have to be compiled with /zw complicates things.