Building conda packages with conda skeleton
This tutorial describes how to quickly build a conda package for a Python module that is already available on PyPI.
In the first procedure, building a simple package, you build a package that can be installed in any conda environment of the same Python version as your root environment. The remaining optional procedures describe how to build packages for other Python versions and other architectures, as well as how to upload packages to your Anaconda.org account.
You may consider using Docker to run the tutorial.
Who is this for?
This tutorial is for Windows, macOS, and Linux users who wish to build a conda package from a PyPI package. No prior knowledge of conda-build or conda recipes is required.
Before you start
Before you start, check the Prerequisites.
Building a simple package with conda skeleton pypi
conda skeleton command picks up the PyPI package metadata
and prepares the conda-build recipe. The final step is to
build the package itself and install it into your conda environment.
It is easy to build a skeleton recipe for any Python package that is hosted on PyPI, the official third-party software repository for the Python programming language.
In this section you are going to use conda skeleton to generate a conda recipe, which informs conda-build about where the source files are located and how to build and install the package.
You'll be working with a package named Click that is hosted on PyPI. Click is a tool for exposing Python functions to create command line interfaces.
First, in your user home directory, run the
conda skeleton pypi click
The two arguments to
conda skeleton are the hosting location,
in this case
pypi, and the name of the package.
This creates a directory named
click and creates one
skeleton file in that directory:
meta.yaml. Many other files can be added
there as necessary, such as
bld.bat, test scripts, or
anything else you need to build your software. For simple, pure-Python recipes,
these extra files are unnecessary and the build/script section in the
is sufficient. Use the
ls command on macOS or Linux or the
dir command on
Windows to verify that this file has been created. The
meta.yaml file has been
populated with information from the PyPI metadata and in many cases will not
need to be edited.
Files in the folder with
meta.yaml are collectively referred to as the "conda-build recipe":
meta.yaml---Contains all the metadata in the recipe. Only the package name and package version sections are required---everything else is optional.
bld.bat---Windows commands to build the package.
build.sh---macOS and Linux commands to build the package.
Now that you have the conda-build recipe ready, you can use conda-build to create the package:
When conda-build is finished, it displays the exact path and
filename of the conda package. See Troubleshooting a sample issue if the
conda-build command fails.
Windows example file path:
macOS example file path:
Linux example file path:
Your path and filename will vary depending on your installation and operating system. Save the path and filename information for the next step.
Now you can install your newly built package in your conda environment by using the use-local flag:
conda install --use-local click
Notice that Click is coming from the local conda-build channel.
(click) 0561:~ jsmith$ conda list # packages in environment at /Users/Jsmith/miniconda/envs/click: # Name Version Build Channel ca-certificates 2019.1.23 0 certifi 2019.3.9 py37_0 click 7.0 py37_0 local
Now verify that Click installed successfully:
Scroll through the list until you find Click.
At this point you now have a conda package for Click that can be installed in any conda environment of the same Python version as your root environment. The remaining optional sections show you how to make packages for other Python versions and other architectures and how to upload them to your Anaconda.org account.
Optional---Building for a different Python version
By default, conda-build creates packages for the version of
Python installed in the root environment. To build packages for
other versions of Python, you use the
--python flag followed
by a version. For example, to explicitly build a version of the
Click package for Python 2.7, use:
conda-build --python 2.7 click
Notice that the file printed at the end of the
output has changed to reflect the requested version of Python.
conda install will look in the package directory for the file
that matches your current Python version.
Windows example file path:
macOS example file path:
Linux example file path:
Your path and filename will vary depending on your installation and operating system. Save the path and filename information for the next task.
Optional---Converting conda package for other platforms
Now that you have built a package for your current platform with
conda-build, you can convert it for use on other platforms with
conda convert command. This works only for pure Python
packages where there is no compiled code. Conda convert does
nothing to change compiled code, it only adapts file paths to
take advantage of the fact that Python scripts are mostly
platform independent. Conda convert accepts a platform specifier
from this and a platform specifier from this list:
In the output directory, 1 folder will be created for each of the 1 or more platforms you chose and each folder will contain a .tar.bz2 package file for that platform.
conda convert -f --platform all C:\Users\jsmith\miniconda\conda-bld\win-64\click-7.0-py37_0.tar.bz2 -o outputdir\
macOS and Linux:
conda convert --platform all /home/jsmith/miniconda/conda-bld/linux-64/click-7.0-py37_0.tar.bz2 -o outputdir/
Change your path and filename to the exact path and filename you saved in Optional---Building for a different Python version.
To use these packages, you need to transfer them to other
computers and place them in the correct
directory for the platform, where
$ARCH can be
A simpler way is to upload all of the bz2 files to Anaconda.org as described in the next task.
If you find yourself needing to use
conda convert, you might
instead prefer to change your recipe to make your package a "noarch" package.
Noarch packages run anywhere and do not require conda convert.
Some of the ecosystem tools don't yet support noarch packages but,
for the most part, noarch packages are a better way to go.
Optional---Uploading packages to Anaconda.org
Anaconda.org is a repository for
public or private packages. Uploading to Anaconda.org allows you
to easily install your package in any environment with just the
conda install command, rather than manually copying or moving the
tarball file from one location to another. You can choose to make
your files public or private. For more information about
Anaconda.org, see the Anaconda.org documentation.
Create a free Anaconda.org account and record your new Anaconda.org username and password.
conda install anaconda-clientand enter your Anaconda.org username and password.
Log into your Anaconda.org account from your terminal with the command
Now you can upload the new local packages to Anaconda.org.
anaconda upload C:\Users\jsmith\miniconda\conda-bld\win-64\click-7.0-py37_0.tar.bz2
macOS and Linux:
anaconda upload /home/jsmith/miniconda/conda-bld/linux-64/click-7.0-py37_0.tar.bz2
Change your path and filename to the exact path and filename you saved in Optional---Building for a different Python version. Your path and filename will vary depending on your installation and operating system.
If you created packages for multiple versions of Python or used
conda convert to make packages for each supported architecture,
you must use the
anaconda upload command to upload each one.
It is considered best practice to create packages for Python
versions 2.7, 3.4, and 3.5 along with all of the architectures.
If you want to always automatically upload a successful
build to Anaconda.org, run:
conda config --set anaconda_upload yes
You can log out of your Anaconda.org account with the command:
Troubleshooting a sample issue
Conda-build may produce the error message "Build Package missing."
To explore this error:
Create a conda skeleton package for skyfield. The
conda skeletoncommand is:
conda skeleton pypi skyfield
This command creates the skyfield conda-build recipe.
conda-build skyfieldand observe that it fails with the following output:
Removing old build environment Removing old work directory BUILD START: skyfield-0.8-py35_0 Using Anaconda Cloud api site https://api.anaconda.org Fetching package metadata: ...... Solving package specifications: . Error: Package missing in current osx-64 channels: - sgp4 >=1.4
In this example, the conda recipe requires
sgp4 for the
skyfield package. The skyfield recipe was created by
conda skeleton. This error means that conda could not find
the sgp4 package and install it.
Since many PyPI packages depend on other PyPI packages to build
or run, the solution is sometimes as simple as using
conda skeleton to create a conda recipe for the missing
package and then building it:
conda skeleton sgp4 conda build sgp4
You may also try using the
--recursive flag with
conda skeleton, but this makes conda recipes for all required
packages, even those that are already available to conda install.
For more options, see the full conda skeleton command documentation.