Strange thing is, it’s still happened :-(, what i have done is.
- Tested to run/build on a VM, lower version than currently problematic windows 10 (1809 x64), lld.exe running fine.
- Thoroughly checked my environment variable %PATH% just in-case there is the same name lld.exe dependencies in which being picked up by lld.exe.
- Turning off windows defender, and to double make sure, adding Xojo installation dir and xojo’s project dir in the exclusion list
- Turning off any windows defender registry customization, turning on windows defender’s cutomization on the ‘working’ VM have no minuses turnback (working fine even with the customization)
- Using Process Monitor to monitor lld.exe and xojo.exe, somehow i couldn’t find anything wrong other than both of them cannot found some of the compiled object (*.o) files.
- Using dependencies walker on the lld.exe in which launched from administrator privilege, the same, nothing wrong with all of the .dll that are being loaded from lld.exe
These are very isolated cases, i hope Xojo team have somekind of debug build for the customer 
Take example this error log :
Linking Executable
C:\\Program Files\\Xojo\\Xojo 2018r4\\Xojo Resources\\Win32\\lld.exe: error: could not open C:\\Users\
ameless\\AppData\\Local\\Temp\\xojo scratch 2424\\dataview1.13.3.xojo_binary_project [EFCBA1EC]\\Windows_x86_64\\/App.o: no such file or directory
C:\\Program Files\\Xojo\\Xojo 2018r4\\Xojo Resources\\Win32\\lld.exe: error: could not open C:\\Users\
ameless\\AppData\\Local\\Temp\\xojo scratch 2424\\dataview1.13.3.xojo_binary_project [EFCBA1EC]\\Windows_x86_64\\/FileTypes1.o: no such file or directory
C:\\Program Files\\Xojo\\Xojo 2018r4\\Xojo Resources\\Win32\\lld.exe: error: C:\\Users\
ameless\\AppData\\Local\\Temp\\xojo scratch 2424\\dataview1.13.3.xojo_binary_project [EFCBA1EC]\\Windows_x86_64\\/CustomData.o: The file was not recognized as a valid object file
Furthermore researching it seems that, HoudiniAssistant64.exe , is a somekind of x64 compiler for the xojo code (llvm), while lld.exe is the linker, based on this wild guess, i fired up Process Monitor and guess what, HoudiniAssistant64.exe is never anywhere in Process Monitor log using any windows API to have anything related about,for example above, App.o, which is should be generating/compiling Xojo code by HoudiniAssistant64.exe into an object file (*.o file extension).
This is a clean freshly installed Windows 10 x64 1809.
If any Xojo team reading this, i don’t mind if there is any special debug tools being run on my windows, even better remote trouble shooting.