When compiling with nopch with UE_ENABLE_ARRAY_SLACK_TRACKING=1
there missing includes in :
Old version :
/Engine/Source/Runtime/Core/Private/HAL/LowLevelMemTracker.cpp
new version
/Engine/Source/Runtime/Core/Private/HAL/LLM/LLM.cpp
Here are the 2 missing includes :
include “Serialization/MemoryWriter.h”
include “Templates/Greater.h”
Maybe we shouldn’t do that 
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Steps to Reproduce
Compile in development with no PCH and UE_ENABLE_ARRAY_SLACK_TRACKING=1
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Hello, thank you for sharing, and sorry for any inconvenience caused by the failed build.
I’ve passed this to the team to fix up. I’ll let you know if they get back with any additional info.
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Thanks, I don’t think we’ve tested that combination locally. Our engine contract is IncludeWhatYouUse, and any missing defines like this are supposed to be detected and pointed out to us to add, but I think our detection misses includes that are needed by some combinations of pound-define.
I added the two includes you called out, plus some other includes that looked like they were only luckily included transitively rather than being explicitly included.
Added in 9b1a0cb992704ec7f183811b06339fd58d44704a
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Thanks [mention removed] and [mention removed]
[mention removed] do you have an EPic tool to detect the breach of contract for IncludeWhatYouUse ?
Thanks!
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Yes, it’s built into UnrealBuildTool: search for IWYUSupport , and see the documentation at https://dev.epicgames.com/documentation/unreal\-engine/include\-what\-you\-use\-iwyu\-for\-unreal\-engine\-programming. That information is be out of date in some respects though, in particular we no longer recommend including CoreMinimal.h as it is too big and monolithic and we recommend the full list of targeted includes instead.
And I think IWYU only checks compile with current define settings, it does not do any analysis of inactive define paths.
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Thanks [mention removed]
Have a great day
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