Contrary to what you might expect, llvmlite does not use any LLVM shared libraries that may be present on the system, or in the conda environment. The parts of LLVM required by llvmlite are statically linked at build time. As a result, installing llvmlite from a binary package does not also require the end user to install LLVM. (For more details on the reasoning behind this, see: Why Static Linking to LLVM?).

Pre-built binaries

Building LLVM for llvmlite is challenging, so we strongly recommend installing a binary package where we have built and tested everything for you. Official conda packages are available in the Anaconda distribution:

conda install llvmlite

Development releases are built from the Git master branch and uploaded to the Numba channel on Anaconda Cloud:

conda install --channel numba llvmlite

Binary wheels are also available for installation from PyPI:

pip install llvmlite

Building manually

Building llvmlite requires first building LLVM. Do not use prebuilt LLVM binaries from your OS distribution or the LLVM website! There will likely be a mismatch in version or build options, and LLVM will be missing certain patches that are critical for llvmlite operation.


Before building, you must have the following:

  • On Windows:
    • Visual Studio 2015 (Update 3) or later, to compile LLVM and llvmlite. The free Express edition is acceptable.
    • CMake installed.
  • On Linux:
    • g++ (>= 4.8) and CMake
    • If building LLVM on Ubuntu, the linker may report an error if the development version of libedit is not installed. If you run into this problem, install libedit-dev.
  • On Mac:
    • Xcode for the compiler tools, and CMake

Compiling LLVM

If you can build llvmlite inside a conda environment, you can install a prebuilt LLVM binary package and skip this step:

conda install -c numba llvmdev

The LLVM build process is fully scripted by conda-build, and the llvmdev recipe is the canonical reference for building LLVM for llvmlite. Please use it if at all possible!

The manual instructions below describe the main steps, but refer to the recipe for details:

  1. Download the LLVM 9.0.1 source code.

  2. Download or git checkout the llvmlite source code.

  3. Decompress the LLVM tar file and apply the following patches from the llvmlite/conda-recipes/ directory. You can apply each patch using the Linux patch -p1 -i {patch-file} command:

    1. llvm-lto-static.patch: Fix issue with LTO shared library on Windows
    2. partial-testing.patch: Enables additional parts of the LLVM test suite
    3. intel-D47188-svml-VF.patch: Add support for vectorized math functions via Intel SVML.
    4. 0001-Revert-Limit-size-of-non-GlobalValue-name.patch: revert the limit put on the length of a non-GlobalValue name
  4. For Linux/macOS:
    1. export PREFIX=desired_install_location CPU_COUNT=N (N is number of parallel compile tasks)
    2. Run the script in the llvmdev conda recipe from the LLVM source directory
  5. For Windows:
    1. set PREFIX=desired_install_location
    2. Run the bld.bat script in the llvmdev conda recipe from the LLVM source directory.

Compiling llvmlite

  1. To build the llvmlite C wrapper, which embeds a statically linked copy of the required subset of LLVM, run the following from the llvmlite source directory:

    python build
  2. If your LLVM is installed in a nonstandard location, set the LLVM_CONFIG environment variable to the location of the corresponding llvm-config or llvm-config.exe executable. This variable must persist into the installation of llvmlite—for example, into a Python environment.

    EXAMPLE: If LLVM is installed in /opt/llvm/ with the llvm-config binary located at /opt/llvm/bin/llvm-config, set LLVM_CONFIG=/opt/llvm/bin/llvm-config.

  3. If you wish to build against an unsupported LLVM version, set the environment variable LLVMLITE_SKIP_LLVM_VERSION_CHECK to non-zero. Note that this is useful for e.g. testing new versions of llvmlite, but support for llvmlite built in this manner is limited/it’s entirely possible that llvmlite will not work as expected. See also: why llvmlite doesn’t always support the latest release(s) of LLVM.


  1. To validate your build, run the test suite by running:



    python -m llvmlite.tests
  2. If the validation is successful, install by running:

    python install

Installing from sdist

If you don’t want to do any modifications to llvmlite itself, it’s also possible to use pip to compile and install llvmlite from the latest released sdist package. You’ll still need to point to your llvm-config if it’s not in the PATH:

LLVM_CONFIG=/path/to/llvm-config pip3 install llvmlite

This should work on any platform that runs Python and llvm. It has been observed to work on arm, ppc64le, and also pypy3 on arm.

x86 users will need to pass an extra flag (see issue #522):

LLVM_CONFIG=/path/to/llvm-config CXXFLAGS=-fPIC pip3 install llvmlite

This is known to work with pypy3 on Linux x64.

It’s also possible to force pip to rebuild llvmlite locally with a custom version of llvm :

LLVM_CONFIG=/path/to/custom/llvm-config CXXFLAGS=-fPIC pip3 install --no-binary :all: llvmlite