how can i fix this error? building 5.3 from source

Development Programming & Scripting C++
1 
ClangRTFM x64 must be installed in order to build this target.
10>Microsoft.MakeFile.Targets(44,5): Error MSB3073 : The command "..\..\Build\BatchFiles\Build.bat AutoRTFMTests Win64 Development -WaitMutex -FromMsBuild" exited with code 6.

whole console log: 5.3 source error - Pastebin.com

1 Like
2

I got this too, trying to build Unreal Engine 5.3 in Windows 11 with MSVC 2022, and I have clang installed.

3

ClangRTFM is not Clang. It’s an internal epic program. I can’t remember what the fix for this is, but it’s not to install Clang.

1 Like
4

To quote Kein from Unreal Slackers,

dont build AutoRTFMTests
remove it from the generated projects or build stuff manually if you use BuildGraph edit the install config/preset

By “remove”, pretty sure he means literally delete the project from your hard disk. Even if you just remove it from the project/solution, it will still build because of the the UE Build Tool.

5

In visual studio, build menu → Configuration manager. Clear the checkbox beside AutoRTFMTests. Build.

Worked for me in vs2022.

9 Likes
6

Try using build solutino(f6) instead of pressing start debug(f5)?
It works for me

1 Like
7

having the same problem, and it does seem it has something todo with Clang

134>ClangRTFM x64 must be installed in order to build this target.
134>F:\Microsoft Visual Studio\2022\Community\MSBuild\Microsoft\VC\v170\Microsoft.MakeFile.Targets(44,5): error MSB3073: The command “…..\Build\BatchFiles\Build.bat AutoRTFMTests Win64 Development -WaitMutex -FromMsBuild” exited with code 6.
134>Done building project “AutoRTFMTests.vcxproj” – FAILED.

The rest of my solution seems to build fine.

8

I made the mistake of building “as is” after the Generate created the project and got this same error. When I looked up how to build, I realized I had forgotten to set the UE5 project as the starter project. After I did that, and a billion years later, it compiled and ran. It has been awhile since I built source, so maybe it was just newb mistake, but thought I would share.

I followed this: Building Unreal Engine from Source | Unreal Engine 5.0 Documentation

4 Likes
9

I installed the v22 of Clang needed for UE5.3 and re-built Development Linux UE5 project (3 settings in Rider, 2 in VS). That did not solve the problem as indicated by some responses. I set bUseAutoRTFMCompiler false in AutoRTFMTests.Target.cs and it fixed some aspects but ran into others. I ended up having to delete the entire folder.

Epic, this module is marked as not-for-licensees so I am curious why it is included in the source drop. Or why there are not instructions for the AutoRTFMCompiler if it is intended for us.

10

Clean everything and redownload source and start source buid from start worked for me.

1 Like
11

Is the AutoRTFMTests project still in your solution? Does it build?

12

Hi there @hamood123213,

This topic has been moved from International to Programming & Scripting: C++.

When posting, please review the categories to ensure your topic is posted in the most relevant space.

Thanks and happy developing!

13

Not sure if you have the same problem as me but I got this error because I missed the step to set UE5 project as startup project by right clicking it.

14

Fix: first you need to Set at started project UE5. press F6 and once is done. press F5

2 Likes
15

Hey, man! Basically, ClangRTFM (as I understood) is a specific distribution inside Unreal and it’s not available for us. If you try to install Clang from the internet, it will only provide you with ‘clang-cl.exe,’ and what the specific project needs is the ‘verse-clang-cl.exe.’ I researched a little bit and put debug messages in the entire building process, and as someone already mentioned, this ‘verse-clang-cl.exe’ and its respective files are located inside a folder named ‘Not-for-licensees.’ So most probably, ‘it’s not for us mere programmers’ haha. If someone from Epic Games can answer us and confirm it, but basically I deleted the whole AutoRTFMTests project and the complete build proceed without any errors =)

2 Likes
16

I added bBuildInSolutionByDefault = false; to ...\Engine\Source\Programs\AutoRTFMTests\AutoRTFMTests.Target.cs to make @TioAlison’s fix survive GenerateProjectFiles.bat re-runs.

17

This does it. Leave it untouched and just don’t build it.