Wiki references unused build variable LLVM_BUILD_INCLUDE_DIR

[jg110]

The wiki build instructions contain this section:

As of 2020-06-23 no pre-built binaries exist for Ubuntu 20.04. sudo apt-get install clang libclang-10-dev and all the other dependencies listed here excluding rapidjson-dev (it is vendored in this repo), then run

cmake -H. -BRelease -DCMAKE_BUILD_TYPE=Release \
   -DCMAKE_PREFIX_PATH=/usr/lib/llvm-10 \
   -DLLVM_INCLUDE_DIR=/usr/lib/llvm-10/include \
   -DLLVM_BUILD_INCLUDE_DIR=/usr/include/llvm-10/

I tried using a similar command with paths for LLVM 15 on the current master (8bc395) got this warning:

-- The CXX compiler identification is GNU 11.2.0
-- The C compiler identification is GNU 13.0.1
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Check for working CXX compiler: /usr/lib64/ccache/c++ - skipped
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Check for working C compiler: /usr/lib64/ccache/cc - skipped
-- Detecting C compile features
-- Detecting C compile features - done
-- Performing Test HAVE_FFI_CALL
-- Performing Test HAVE_FFI_CALL - Success
-- Found FFI: /usr/lib64/libffi.so  
-- Performing Test Terminfo_LINKABLE
-- Performing Test Terminfo_LINKABLE - Success
-- Found Terminfo: /usr/lib64/libtinfo.so  
-- Found ZLIB: /usr/lib64/libz.so (found version "1.2.13")  
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD
-- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Success
-- Found Threads: TRUE  
-- RapidJSON found. Headers: /usr/include
fatal: No names found, cannot describe anything.
-- Configuring done (1.0s)
-- Generating done (0.0s)
CMake Warning:
  Manually-specified variables were not used by the project:

    LLVM_BUILD_INCLUDE_DIR

-- Build files have been written to: /home/jg110/Documents/repos/ccls/Release

I haven't checked to see how long ago this variable was removed, but if it was long enough ago that current builds wouldn't be using that variable, perhaps the wiki should be updated to remove the reference to LLVM_BUILD_INCLUDE_DIR.