I checked, I have these files on disk with the same exact case. For example, this is a file path from disk, like it is: c:\Unreal\UnrealEngine-release-4.18\Engine\Source\Runtime\CoreUObject\Public\CoreUObjectSharedPCH.h
if I use v9_clang-4.0.0-centos7 and blueprint nativization setting in DefaultGame.ini - it fails with one of the blueprints failing with fatal error: UTF-16 (LE) byte order mark detected ([see file])
Cool, yeah if that wasn’t intentional I’d check your Blueprint asset in the editor and correct the function name there, then rebuild the cooked target with Blueprint nativization enabled. That should do the trick.
For some reason the disk drive is spelled with a small “c” letter, which causes a case-sensitivity warning. Arguably in this case it should not apply (hard to imagine a path with “C:” in it being portable), but that unfortunately would need fixing in clang. You can remove -Wnonportable-include-path from LinuxToolChain.cs, although I would try to first fix the reason for lowercase “c”.
According to Windows, my drive is not “C”, it is “c”, so path is actually correct.
RCL, it does not look like “-Wnonportable-include-path” is in LinuxToolChain.cs: \Engine\Source\Programs\UnrealBuildTool\Platform\Linux\LinuxToolChain.cs