pbr - Python Build Reasonableness
A library for managing setuptools packaging needs in a consistent manner.
pbr reads and then filters the setup.cfg data through a setup hook to fill in default values and provide more sensible behaviors, and then feeds the results in as the arguments to a call to setup.py - so the heavy lifting of handling python packaging needs is still being done by setuptools.
Note that we don’t support the easy_install aspects of setuptools: while we depend on setup_requires, for any install_requires we recommend that they be installed prior to running setup.py install - either by hand, or by using an install tool such as pip.
What It Does
PBR can and does do a bunch of things for you:
- Version: Manage version number based on git revisions and tags
- AUTHORS: Generate AUTHORS file from git log
- ChangeLog: Generate ChangeLog from git log
- Manifest: Generate a sensible manifest from git files and some standard files
- Sphinx Autodoc: Generate autodoc stub files for your whole module
- Requirements: Store your dependencies in a pip requirements file
- long_description: Use your README file as a long_description
- Smart find_packages: Smartly find packages under your root package
Notes for Package maintainers
If you are maintaining packages of software that uses pbr, there are some features you probably want to be aware of that can make your life easier. They are exposed by environment variables, so adding them to rules or spec files should be fairly easy.
pbr, when run in a git repo, derives the version of a package from the git tags. When run in a tarball with a proper egg-info dir, it will happily pull the version from that. So for the most part, the package maintainers shouldn’t need to care. However, if you are doing something like keeping a git repo with the sources and the packaging intermixed and it’s causing pbr to get confused about whether its in its own git repo or not, you can set PBR_VERSION:
and all version calculation logic will be completely skipped and the supplied version will be considered absolute.
Distribution version numbers
pbr will automatically calculate upstream version numbers for dpkg and rpm using systems. Releases are easy (and obvious). When packaging preleases though things get more complex. Firstly, semver does not provide for any sort order between pre-releases and development snapshots, so it can be complex (perhaps intractable) to package both into one repository - we recommend with either packaging pre-release releases (alpha/beta/rc’s) or dev snapshots but not both. Secondly, as pre-releases and snapshots have the same major/minor/patch version as the version they lead up to, but have to sort before it, we cannot map their version naturally into the rpm version namespace: instead we represent their versions as versions of the release before.
As of 1.0.0 pbr doesn’t alter the dependency behaviour of setuptools.
Older versions would invoke pip internally under some circumstances and required the environment variable SKIP_PIP_INSTALL to be set to prevent that. Since 1.0.0 we now document that dependencies should be installed before installing a pbr using package. We don’t support easy install, but neither do we interfere with it today. If you observe easy install being triggered when building a binary package, then you’ve probably missed one or more package requirements.
Note: we reserve the right to disable easy install via pbr in future, since we don’t want to debug or support the interactions that can occur when using it.
pbr includes everything in a source tarball that is in the original git repository. This can again cause havoc if a package maintainer is doing fancy things with combined git repos, and is generating a source tarball using python setup.py sdist from that repo. If that is the workflow the packager is using, settingSKIP_GIT_SDIST:
will cause all logic around using git to find the files that should be in the source tarball to be skipped. Beware though, that because pbr packages automatically find all of the files, most of them do not have a complete MANIFEST.in file, so its possible that a tarball produced in that way will be missing files.
AUTHORS and ChangeLog
pbr generates AUTHORS and ChangeLog files from git information. This can cause problem in distro packaging if package maintainer is using git repository for packaging source. If that is the case settingSKIP_GENERATE_AUTHORS
will cause logic around generating AUTHORS using git information to be skipped. Similarly settingSKIP_WRITE_GIT_CHANGELOG
will cause logic around generating ChangeLog file using git information to be skipped.