WARNING - Can't find a Python library, got libdir=None, ldlibrary=None, multiarch=None, masd=None

Question

Trying to install llama-cpp-python with "pip install llama-cpp-python". It is failing with following error.

pip install llama-cpp-python
Collecting llama-cpp-python
  Using cached llama_cpp_python-0.2.20.tar.gz (8.7 MB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
  Installing backend dependencies ... done
  Preparing metadata (pyproject.toml) ... done
Requirement already satisfied: typing-extensions>=4.5.0 in c:\mydata\installations\ai\envs\privategpt\lib\site-packages (from llama-cpp-python) (4.8.0)
Requirement already satisfied: numpy>=1.20.0 in c:\mydata\installations\ai\envs\privategpt\lib\site-packages (from llama-cpp-python) (1.26.0)
Requirement already satisfied: diskcache>=5.6.1 in c:\mydata\installations\ai\envs\privategpt\lib\site-packages (from llama-cpp-python) (5.6.3)
Building wheels for collected packages: llama-cpp-python
  Building wheel for llama-cpp-python (pyproject.toml) ... error
  error: subprocess-exited-with-error

  × Building wheel for llama-cpp-python (pyproject.toml) did not run successfully.
  │ exit code: 1
  ╰─> [644 lines of output]
      *** scikit-build-core 0.7.0 using CMake 3.27.7 (wheel)
      *** Configuring CMake...
      2023-12-01 16:56:53,129 - scikit_build_core - WARNING - Can't find a Python library, got libdir=None, ldlibrary=None, multiarch=None, masd=None
      loading initial cache file C:\Users\vard~1\AppData\Local\Temp\tmpe8xr4tpk\build\CMakeInit.txt
      -- Building for: Visual Studio 15 2017
      -- Selecting Windows SDK version 10.0.22621.0 to target Windows 10.0.22000.
      -- The C compiler identification is MSVC 19.16.27035.0
      -- The CXX compiler identification is MSVC 19.16.27035.0
      -- Detecting C compiler ABI info
      -- Detecting C compiler ABI info - done
      -- Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio/2017/BuildTools/VC/Tools/MSVC/14.16.27023/bin/Hostx86/x64/cl.exe - skipped
      -- Detecting C compile features
      -- Detecting C compile features - done
      -- Detecting CXX compiler ABI info
      -- Detecting CXX compiler ABI info - done
      -- Check for working CXX compiler: C:/Program Files (x86)/Microsoft Visual Studio/2017/BuildTools/VC/Tools/MSVC/14.16.27023/bin/Hostx86/x64/cl.exe - skipped
      -- Detecting CXX compile features
      -- Detecting CXX compile features - done
      -- Found Git: C:/Program Files/Git/cmd/git.exe (found version "2.37.2.windows.2")
      -- Performing Test CMAKE_HAVE_LIBC_PTHREAD
      -- Performing Test CMAKE_HAVE_LIBC_PTHREAD - Failed
      -- Looking for pthread_create in pthreads
      -- Looking for pthread_create in pthreads - not found
      -- Looking for pthread_create in pthread
      -- Looking for pthread_create in pthread - not found
      -- Found Threads: TRUE
      -- CMAKE_SYSTEM_PROCESSOR: AMD64
      -- CMAKE_GENERATOR_PLATFORM: x64
      -- x86 detected
      -- Performing Test HAS_AVX_1
      -- Performing Test HAS_AVX_1 - Success
      -- Performing Test HAS_AVX2_1
      -- Performing Test HAS_AVX2_1 - Success
      -- Performing Test HAS_FMA_1
      -- Performing Test HAS_FMA_1 - Success
      -- Performing Test HAS_AVX512_1
      -- Performing Test HAS_AVX512_1 - Failed
      -- Performing Test HAS_AVX512_2
      -- Performing Test HAS_AVX512_2 - Failed
      CMake Warning (dev) at CMakeLists.txt:20 (install):
        Target llama has PUBLIC_HEADER files but no PUBLIC_HEADER DESTINATION.
      This warning is for project developers.  Use -Wno-dev to suppress it.

      CMake Warning (dev) at CMakeLists.txt:29 (install):
        Target llama has PUBLIC_HEADER files but no PUBLIC_HEADER DESTINATION.
      This warning is for project developers.  Use -Wno-dev to suppress it.

      -- Configuring done (27.2s)
      -- Generating done (0.3s)
      -- Build files have been written to: C:/Users/vard/AppData/Local/Temp/tmpe8xr4tpk/build
      *** Building project with Visual Studio 15 2017...
      Change Dir: 'C:/Users/vard/AppData/Local/Temp/tmpe8xr4tpk/build'

      Run Build Command(s): "C:/Program Files (x86)/Microsoft Visual Studio/2017/BuildTools/MSBuild/15.0/Bin/MSBuild.exe" ALL_BUILD.vcxproj /p:Configuration=Release /p:Platform=x64 /p:VisualStudioVersion=15.0 /v:n
      Microsoft (R) Build Engine version 15.9.21+g9802d43bc3 for .NET Framework
      Copyright (C) Microsoft Corporation. All rights reserved.
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  *** CMake build failed
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
  ERROR: Failed building wheel for llama-cpp-python
Failed to build llama-cpp-python
ERROR: Could not build wheels for llama-cpp-python, which is required to install pyproject.toml-based projects

Needed suggestions for successful installation

Answer 1

This looks like a known issue:

Don't include the full URL to the wheel in the index URL. pip is designed to search for the wheel itself in package indices:

python -m pip install llama-cpp-python --prefer-binary --no-cache-dir --extra-index-url=https://jllllll.github.io/llama-cpp-python-cuBLAS-wheels/AVX2/cu122

Link to git : https://github.com/abetlen/llama-cpp-python/issues/721#issuecomment-1723892241