LLDB has a powerful scripting interface which is accessible through Python. Python is available either from withing LLDB through a (interactive) script interpreter, or as a Python module which you can import from the Python interpreter.

To make this possible, LLDB links against the Python shared library. Linking against Python comes with some constraints to be aware of.

  1. It is not possible to build and link LLDB against a Python 3 library and use it from Python 2 and vice versa.
  2. It is not possible to build and link LLDB against one distribution on Python and use it through a interpreter coming from another distribution. For example, on macOS, if you build and link against Python from, you cannot import the lldb module from the Python interpreter installed with Homebrew.
  3. To use third party Python packages from inside LLDB, you need to install them using a utility (such as pip) from the same Python distribution as the one used to build and link LLDB.

The previous considerations are especially important during development, but apply to binary distributions of LLDB as well. For example, the LLDB that comes with Xcode links against the Python 3 that’s part of Xcode. Therefore you should always use the Python in Xcode (through xcrun python3 or /usr/bin/python3) to import the lldb module or install packages.