pygame / doc / RELEASE.txt

Pygame2 release management

The following sections will deal with a quick guide about what to take care
of before issueing a new release.

Releases are split into three phases usually, *alpha*, *rc* and *final*.

Alpha phase
The *alpha* phase usually takes place as soon as a *final* release was made and
can feature as many releases as necessary. *alpha* releases should be made
whenever large changes were made, which change the behaviour, API interfaces or
add completely new stuff.

*alpha* release versions are tagged with a *-alphaXXX* suffix, where *XXX* is
the *XXXth* release within that alpha phase. There is no limit to the amount of
releases to be made.

Release Candidate phase
The *rc* phase (short for Release Candidate) enters a beta testing cycle, where
no new features should be added, but only bug fixes be committed. It is also
the right time for proof-reading the documentation, running the unit tests on
all platforms again and again and to recheck all examples.

*rc* release versions are tagged with a *-rcXX* suffix, where *XXX* is
the *XXXth* release within that *rc* phase. There should not be more than 3
*rc* releases by default and they should be released on a weekly basis, allowing
adopters to have a minimum of one week and maximum of 3 weeks before the final
release is made.

Final phase
This is not directly a phase on its own, but simply the day of the final release
for the specific version. The *final* release usually should be the same as the
last *rc* release, but only differ by the version number and release date.

Before a new release takes place, the following steps have to be made:

* Increase version number (see `Postprocessing`) in ::
* Update NEWS.txt with the changes since the last version (only for final
  releases - alpha and rc should contain the information, but not be tagged
  explicitly). See `Editing News` for more information.

* Update README.txt and doc/BuildXXX.txt to point to the latest required
  dependency versions.

* Make sure, all tests for all supported Python versions work on all
  platforms. ::

  make clean
  make purge_installs
  make installall
  make testall
  make testall2

Editing News
The NEWS.txt file contains information about the changes between two
*final* releases. If possible, it should be always up to date with the
latest SVN changes.

For adding a new release entry, the following layout is used: ::

  Released on DATE.
  [Change list]

  Test releases:
  [Release list with revisions]

Each important change that has any impact on the API (be it bug fixes,
behaviour changes or whatever else), should be described here. If it was
a user-submitted fix or change, credits are given to the user. If it was
a fix for some user-submitted bug report, a short pointer to the report
location should be given. If it was a fix for some bug tracker entry, the
tracker id should be added. ::

  Released on 2034-12-20.
  * Added foo.morefoo class.
  * Bug: Fixed () misbehaviour for string arguments (via mailing list).
  * Added foo.barbaz () method for whatever (thanks to Emily Doe).
  * Bug #1234: Fixed foo.foobar() return value.

  Test releases:
  * alpha 1 (rev. 73213)
  * alpha 2 (rev. 73237)
  * rc 1 (rev. 73244)

Once anything's tested, updated written down, the required packages have to be
built. First of all, the source packages are required as the binary packages
will be built using them. ::

    make release

This also will create a set of bundled docs to be distributed.

Win32 installers
For Win32 platforms, binary builds (MSI packages) for the Python versions
*2.4*, *2.5*, *2.6* and *3.0* have to be made, based on one of the source
packages, which were just created. ::

  # For Python 2.4
  c:\PythonXX\python.exe build bdist_wininst
  # For Python > 2.4
  c:\PythonXX\python.exe build bdist_msi

Once all installers are available, make sure they work and ship anything
required by running the unit tests: ::

  # Under Msys:
  make testall
  # Win32 CMD prompt (do that for all versions):
  c:\PythonXX\python.exe -c "import pygame2.test; ()"

Mac OS X installers
*TODO: Instructions for Mac OS X platforms*

Once all packages are built the revision control tree can be tagged with the
new version, the packages be published and an announcement sent to the mailing

Right after a release has been made and the tree was tagged correctly, the
version numbers should be increased (and revised just before the next release).

The release number is split into three parts, a *MAJOR*, *MINOR* and *BUGFIX*

* *BUGFIX* should be increased by one, whenever bug fixes have been made
  between two releases.

* *MINOR* should be increased, whenever changes or additions to the API were
  made. This also will cause *BUGFIX* to be set back to 0.

* *MAJOR* should be increased, whenever outstanding additions or changes to the
  API were made, which legitimate it.

Why is that *MINOR*/*BUGFIX* diversion important? Pygame2 is basically some
sort of library. As such, people can write software with it while not
necessarily including the library code (Pygame2 itself). So what happens, if a
user has some version installed, where certain API interfaces changed and behave
differently from the version, the developer worked with? The program is most
likely to fail and the user will blame either the developer or the library.

With a consistent versioning scheme, developers can test against versions
explicitly to guarantee the functionality with those. Users can receive an
explicit notice, if their installed version might be incompatible and react
upon that accordingly.

How does that look like in practice? ::

  Event/Action                     Version number
  Initial release                      2.0.0
  Some fixes done                      2.0.1
  More fixes done                      2.0.2
  Some additions                       2.1.0
  Some fixes (again)                   2.1.1
  More fixes                           2.1.2
  More fixes                           2.1.3
  Some additions                       2.2.0
  Important major changes              3.0.0
  ...                                   ...