make llvm issue, build directory does not exist

[zarosath]

CMake Error: The source directory "/home/william/b3d/build/llvm/build" does not exist.
Specify --help for usage, or press the help button on the CMake GUI.
Makefile:106: recipe for target 'llvm' failed

ubuntu 18.04

[kfprimm]

Please provide the exact commands you ran.