Installing

Requirements

• Python 3.8+ (CPython, or PyPy 3.9+)

• libmemcached 1.0.8 or later (tested with 1.0.18 and 1.1.4; 1.1.x is the maintained awesomized/libmemcached fork, which builds with CMake)

• zlib (required for compression support)

• libsasl2 (required for authentication support)

Building

Like any Python package, use setup.py:

$ python setup.py install --with-libmemcached=/opt/local

You only need to specify --with-libmemcached if libmemcached is not available on your C compiler’s include and library path. This is the case if you use MacPorts or something like that.

So for example, if one were to use MacPorts to install libmemcached, your libmemcached would end up in /opt/local, hence --with-libmemcached=/opt/local.

Using pip you achieve the same thing as follows:

pip install pylibmc --install-option="--with-libmemcached=/opt/local"

Note that /usr/local is typically on the library search path. If it is not, you’d probably want to fix that instead.

Homebrew and MacOS

brew install libmemcached pip install pylibmc

Choosing a libmemcached

With several libmemcached installs on one machine, point the build at the one you want, either with the LIBMEMCACHED environment variable or --with-libmemcached:

LIBMEMCACHED=/opt/libmemcached-1.1.4 pip install pylibmc

The build then links that exact library file and records its directory as an rpath ahead of any library path supplied by the Python interpreter (some Python builds, e.g. pyenv on Homebrew systems, put -L/opt/homebrew/lib first). Check what you got with pylibmc.build_info(); _pylibmc.libmemcached_runtime_version is the version of the library actually loaded, and importing pylibmc warns if its major.minor differs from the headers it was compiled against.

When rebuilding, remove stale build/ directories first, since pip builds in the source tree and may reuse objects compiled against other headers.