python-build is a pyenv plugin that
provides a pyenv install
command to compile and install different versions
of Python on UNIX-like systems.
You can also use python-build without pyenv in environments where you need precise control over Python version installation.
See the list of releases for changes in each version.
Since python-build is bundled with pyenv by default, you do not need to do anything.
Installing python-build as a standalone program will give you access to the
python-build
command for precise control over Python version installation. If you
have pyenv installed, you will also be able to use the pyenv install
command.
git clone https://github.com/pyenv/pyenv.git
cd pyenv/plugins/python-build
./install.sh
This will install python-build into /usr/local
. If you do not have write
permission to /usr/local
, you will need to run sudo ./install.sh
instead.
You can install to a different prefix by setting the PREFIX
environment
variable.
To update python-build after it has been installed, run git pull
in your cloned
copy of the repository, then re-run the install script.
Mac OS X users can install python-build with the Homebrew
package manager. This will give you access to the python-build
command. If you
have pyenv installed, you will also be able to use the pyenv install
command.
This is the recommended method of installation if you installed pyenv with Homebrew.
brew install pyenv
Or, if you would like to install the latest development release:
brew install --HEAD pyenv
Before you begin, you should ensure that your build environment has the proper system dependencies for compiling the wanted Python Version (see our recommendations).
To install a Python version for use with pyenv, run pyenv install
with
exact name of the version you want to install. For example,
pyenv install 2.7.4
Python versions will be installed into a directory of the same name under
~/.pyenv/versions
.
To see a list of all available Python versions, run pyenv install --list
. You
may also tab-complete available Python versions if your pyenv installation is
properly configured.
If you have installed python-build as a standalone program, you can use the
python-build
command to compile and install Python versions into specific
locations.
Run the python-build
command with the exact name of the version you want to
install and the full path where you want to install it. For example,
python-build 2.7.4 ~/local/python-2.7.4
To see a list of all available Python versions, run python-build --definitions
.
Pass the -v
or --verbose
flag to python-build
as the first argument to see
what's happening under the hood.
Both pyenv install
and python-build
accept a path to a custom definition file
in place of a version name. Custom definitions let you develop and install
versions of Python that are not yet supported by python-build.
See the python-build built-in definitions as a starting point for custom definition files.
Without the user customizing the build with environment variables (see below),
python-build
builds Python with mostly default Configure options
to maintain the principle of the least surprise.
The exceptions -- non-default options that are set by default -- are listed below:
Option/Behavior | Rationale |
---|---|
--enable-shared is on by default. Pass --disable-shared to Configure options to override |
The official CPython Docker image uses it. It's required to embed CPython. |
argument to --enable-universalsdk is ignored and set to / |
|
--with-universal-archs defaults to universal2 on ARM64 architecture |
the only dual-architecture Macs in use today are Apple Silicon which can only build that one |
argument to --enable-framework is ignored and set to a specific value |
CPython's build logic requires a very specific argument to avoid installing the Applications part globally |
argument to --enable-unicode in non-MacOS is overridden to ucs4 for 2.x-3.3 |
|
MACOSX_DEPLOYMENT_TARGET defaults to the running MacOS version |
Homebrew is used to find dependency packages if brew
is found on PATH
:
- In MacOS, or
- If the running Pyenv itself is installed with Homebrew
Set PYTHON_BUILD_USE_HOMEBREW
or PYTHON_BUILD_SKIP_HOMEBREW
to override this default.
When Homebrew is used, its include
and lib
paths are added to compiler search path (the latter is also set as rpath
),
and also Python dependencies that are typically keg-only are searched for in the Homebrew installation and added individually.
NOTE: Homebrew is not used in Linux by default because it's rolling-release which causes a problem.
Upgrading a Python dependency in Homebrew to a new major version (that brew
does without warning)
would break all Pyenv-managed installations that depend on it.
You can use a community plugin fix-version
to fix installations in such a case.
In FreeBSD, if pkg
is on PATH, Ports are searched for some dependencies that Configure is known to not search for via pkg-config
.
(Later versions of CPython search for more packages via pkg-config
so this may eventually become redundant.)
You can set certain environment variables to control the build process.
TMPDIR
sets the location where python-build stores temporary files.PYTHON_BUILD_BUILD_PATH
sets the location in which sources are downloaded and built. By default, this is a subdirectory ofTMPDIR
.PYTHON_BUILD_CACHE_PATH
, if set, specifies a directory to use for caching downloaded package files.PYTHON_BUILD_MIRROR_URL
overrides the default mirror URL root to one of your choosing.PYTHON_BUILD_MIRROR_URL_SKIP_CHECKSUM
, if set, does not append the SHA2 checksum of the file to the mirror URL.PYTHON_BUILD_SKIP_MIRROR
, if set, forces python-build to download packages from their original source URLs instead of using a mirror.PYTHON_BUILD_HTTP_CLIENT
, explicitly specify the HTTP client type to use.aria2
,curl
andwget
are the supported values and by default, are searched in that order.PYTHON_BUILD_CURL_OPTS
,PYTHON_BUILD_WGET_OPTS
,PYTHON_BUILD_ARIA2_OPTS
pass additional parameters to the corresponding HTTP client.PYTHON_BUILD_SKIP_HOMEBREW
, if set, will not search for libraries installed by Homebrew when it would normally will.PYTHON_BUILD_USE_HOMEBREW
, if set, will search for libraries installed by Homebrew when it would normally not.PYTHON_BUILD_HOMEBREW_OPENSSL_FORMULA
, override the Homebrew OpenSSL formula to use.PYTHON_BUILD_ROOT
overrides the default location from where build definitions inshare/python-build/
are looked up.PYTHON_BUILD_DEFINITIONS
can be a list of colon-separated paths that get additionally searched when looking up build definitions.CC
sets the path to the C compiler.PYTHON_CFLAGS
lets you pass additional options to the defaultCFLAGS
. Use this to override, for instance, the-O3
option.CONFIGURE_OPTS
lets you pass additional options to./configure
.MAKE
lets you override the command to use formake
. Useful for specifying GNU make (gmake
) on some systems.MAKE_OPTS
(orMAKEOPTS
) lets you pass additional options tomake
.MAKE_INSTALL_OPTS
lets you pass additional options tomake install
.PYTHON_CONFIGURE_OPTS
andPYTHON_MAKE_OPTS
andPYTHON_MAKE_INSTALL_OPTS
allow you to specify configure and make options for building CPython. These variables will be passed to Python only, not any dependent packages (e.g. libyaml).
Both pyenv install
and python-build
support the --patch
(-p
) flag that
signals that a patch from stdin should be applied to Python, Jython or PyPy
source code before the ./configure
and compilation steps.
Example usage:
# applying a single patch
$ pyenv install --patch 2.7.10 < /path/to/python.patch
# applying a patch from HTTP
$ pyenv install --patch 2.7.10 < <(curl -sSL http://git.io/python.patch)
# applying multiple patches
$ cat fix1.patch fix2.patch | pyenv install --patch 2.7.10
You can build CPython with --enable-shared
to install a version with
shared object.
If --enable-shared
was found in PYTHON_CONFIGURE_OPTS
or CONFIGURE_OPTS
,
python-build
will automatically set RPATH
to the pyenv's prefix directory.
This means you don't have to set LD_LIBRARY_PATH
or DYLD_LIBRARY_PATH
for
the version(s) installed with --enable-shared
.
$ env PYTHON_CONFIGURE_OPTS="--enable-shared" pyenv install 2.7.9
Building CPython with --enable-optimizations
will result in a faster
interpreter at the cost of significantly longer build times. Most notably, this
enables PGO (profile guided optimization). While your mileage may vary, it is
common for performance improvement from this to be in the ballpark of 30%.
env PYTHON_CONFIGURE_OPTS='--enable-optimizations --with-lto' PYTHON_CFLAGS='-march=native -mtune=native' pyenv install 3.6.0
You can also customize the task used for profile guided optimization by setting
the PROFILE_TASK
environment variable, for instance, PROFILE_TASK='-m test.regrtest --pgo -j0'
will run much faster than the default task.
If you have the shasum
, openssl
, or sha256sum
tool installed, python-build will
automatically verify the SHA2 checksum of each downloaded package before
installing it.
Checksums are optional and specified as anchors on the package URL in each definition. (All bundled definitions include checksums.)
python-build will first attempt to download package files from a mirror hosted on GitHub Pages. If a package is not available on the mirror, if the mirror is down, or if the download is corrupt, python-build will fall back to the official URL specified in the definition file.
You can point python-build to another mirror by specifying the
PYTHON_BUILD_MIRROR_URL
environment variable--useful if you'd like to run your
own local mirror, for example. Package mirror URLs are constructed by joining
this variable with the SHA2 checksum of the package file.
If the mirror being used does not have the same checksum (e.g. with a
pull-through cache like Artifactory), you can set the
PYTHON_BUILD_MIRROR_URL_SKIP_CHECKSUM
environment variable.
If you don't have an SHA2 program installed, python-build will skip the download
mirror and use official URLs instead. You can force python-build to bypass the
mirror by setting the PYTHON_BUILD_SKIP_MIRROR
environment variable.
The official python-build download mirror is provided by GitHub Pages.
You can instruct python-build to keep a local cache of downloaded package files
by setting the PYTHON_BUILD_CACHE_PATH
environment variable. When set, package
files will be kept in this directory after the first successful download and
reused by subsequent invocations of python-build
and pyenv install
.
The pyenv install
command defaults this path to ~/.pyenv/cache
, so in most
cases you can enable download caching simply by creating that directory.
Both python-build
and pyenv install
accept the -k
or --keep
flag, which
tells python-build to keep the downloaded source after installation. This can be
useful if you need to use gdb
and memprof
with Python.
Source code will be kept in a parallel directory tree ~/.pyenv/sources
when
using --keep
with the pyenv install
command. You should specify the
location of the source code with the PYTHON_BUILD_BUILD_PATH
environment
variable when using --keep
with python-build
.
Please see the pyenv wiki for solutions to common problems.
If you can't find an answer on the wiki, open an issue on the issue tracker. Be sure to include the full build log for build failures.
If you are contributing a new python version for python-build, you can test the build in a docker container based on Ubuntu 18.04.
With docker installed:
docker build -t my_container .
docker run my_container pyenv install <my_version>
To enter a shell which will allow you to build and then test a python version, replace the second line with
docker run -it my_container
The container will need to be rebuilt whenever you change the repo, but after the first build, this will be very fast, as the layer including the build dependencies will be cached.
Changes made inside the container will not be persisted.
To test all new versions since a particular revision (e.g. master
), cd
to the root of your pyenv
repo, and run this script:
set -e
set -x
docker build -t pyenv-test-container .
git diff --name-only master \
| grep '^plugins/python-build/share/python-build/' \
| awk -F '/' '{print $NF}' \
| xargs -I _ docker run pyenv-test-container pyenv install _
- Build the docker image with the tag pyenv-test-container
- Look for the names files changed since revision
master
- Filter out any which don't live where python-build keeps its build scripts
- Look only at the file name (i.e. the python version name)
- Run a new docker container for each, building that version