[5.8] InstalledEngine build output missing *Classes.h files that are generated from UHT

We are upgrading our project from 5.7 to 5.8 and without modifications, we are seeing missing *Classes.h files in Intermediates, within the output of the InstalledEngine build.

For local developers building from source, this is not an issue as the file is generated by UHT, but without adding explicit filter to InstalledEngineFilters.xml, these types of UHT files don’t actually make it into the installed engine.

Another file that is impacted, and that we ran into was BlueprintGraphClasses.h which is referenced in the VisualStudioTools plugin.

While this thread was solved in another way, it can also be solved by adding a filter to the InstalledEngineFilters.xml

[[Help] UE 5.8 Cannot install VisualStudioTools plugin with compile error “cannot open include file: ‘BlueprintGraphClasses.h’” - Programming & Scripting / C++ - Epic Developer Community Forums]([Help] UE 5.8 Cannot install VisualStudioTools plugin with compile error “cannot open include file: ‘BlueprintGraphClasses.h’”)

While the adding explicit filters does work, that is probably masking the root cause. Any help on getting to the root cause would be much appreciated.

If not, at least we’ve raised the issue for others to see.

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Steps to Reproduce
-Run an InstalledEngine build in 5.7 (-target=Make Installed Build Win64)

-Inspect .\LocalBuilds\Engine\Windows\Engine\Intermediate\Build\Win64\UnrealEditor\Inc\GameplayTags\UHT\…

-Observe GameplayTagsClasses.h is present

-Run an InstalledEngine build in 5.8 (-target=Make Installed Build Win64)

-Inspect .\LocalBuilds\Engine\Windows\Engine\Intermediate\Build\Win64\UnrealEditor\Inc\GameplayTags\UHT\…

-Observe GameplayTagsClasses.h is MISSING

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Hello!

Can you share the full command line you are using for the Installed Build? I would also need to know how\when you procured the sources.

Regards,

Martin

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Hello!

I won’t need your command as I was able to validate the problem happens with the launcher distribution. I was able to find the source of the problem but I don’t have a fix at this moment.

You should be able to work around the problem by avoiding to include those generated headers and favor individual include statements. These headers are vestige from the past and can massively include other headers which increase the compilation times. The engine is not depending on them anymore for that reason.

I will come back with more details as they surface.

Regards,

Martin

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Hello!

We submitted a fix that restore the copy of the generated Classes header in Installed Build to the Release 5.8 stream (CL56702042\ GH commit). This will be part of the upcoming 5.8.2 hotfix.

Regards,

Martin

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