This page contains details about how to release a new version of FlightGear into the wild. It is a continous work in progress to be improved with every every new release.
This release plan was originally developed by Mathias Fröhlich, Martin Spott, Thorsten Brehm and Torsten Dreyer during LinuxTag 2011.
If you think you have something to contribute to the release process, feel free to. Please discuss this concept at the mailing-list.
General Release Concept
New FlightGear releases will be scheduled twice a year. The magic number to remember is 17 (we tried 42, but that didn't turn out so well. 17 is perfect: 1 is a prime, 7 is a prime and so is 17). On the 17th of January (1) and July (7) a new release branch will be created for SimGear, FlightGear and FGDATA.
After branching, we will allow one month for bug fixing in the release branch, so building and packing of the binaries and FGDATA will take place around February, 18th and August, 18th. Allowing a few days for distribution of the files, new versions should be publically available around the 20th of February and August.
The development stream of SimGear, FlightGear and FGDATA will be set into a frozen state one month before the branch-day (17th) to let the dust of development settle and to allow fixing the most annoying bugs in the code. During this period, developers are requested not to add any new features, subsystems or alike. Immediately after the stream has branched for the release, development in the main stream (next/master) is open for major changes until one month before the next branch-day. This results in a duty cycle of 5 month developing and 1 month thinking.
Releases will have even version numbers (2.2.0, 2.4.0, 2.6.0), bugfix releases will increase their least significant digit (2.2.0, 2.2.1, 2.2.2, 2.2.3). The Development stream uses odd version numbers and is usually on number higher than the current release (Released is 2.4.0, development stream is 2.5.0, next release will be 2.6.0).
The Major version number will be increased after significant changes to the functionality of the software.
Detailed Time Schedule
- Dec/Jun 17th: Development stream is declared "frozen" or "red".
- Jan/Jul 17th: Create new Release branch, assign new version number to dev-stream
- declare dev-stream "open" or "green", create binaries for RC0 from release-branch
- Feb/Aug 17th: Create binaries/installers, pack fgdata, publish files, announce new version, declare release-branch "closed"
From step 1) to step 2), no new features or major changes shall be pushed onto the development stream (neither source nor data). This period is for preparing the code for the release and make sure there are no major issues.
After step 2) to the next step 1), development on the next/master stream is open again for any change. Bugfixes for this release go into the release branch only and gets a better fix in the dev-stream. Fixes that need to be in both branches go into the release branch and get backported into the next/master my merging, cherry-picking or whatever method applies (note: this needs to be discussed).
The bugtracker will be our primary source for the bug fixing period. Bugs reported on the mailing list or forum will not be tracked! Reporters shall be requested to file a bug report at the bugtracker. Bugs shall be assigned a priority and a keyword to make the assignment to a developer easier. Bug reports that can't be confirmed or need more input from the reporter to get fixed will be assigned a new state "stalled" and only processed after more information has been provided. Bugs assigned a high priority will be downgraded, if no progress has been made over a certain amount of time. This is to prevent the release from being blocked by a bug that no developer is able (or willing) to fix. The only exception is "does not compile for one of the major platforms", which certainly is a release-blocker.
The current branch for the never release version 2.2.0 will be left untouched. No release will be created from this branch. The next/master branches will receive a new development version number 2.3.0 soon. The first release branch will be created on Jul, 17th 2011. The first freeze for the branches will be announced on Jun, 17th 2011. If everything goes well, Version 2.4.0 will be available around Aug, 18th 2011.
Tasks and Owners
(taskowners not yet assigned)
- Announce the state-change of the dev-streams
- Create/maintain the git branches
- Track the bugs on the tracker, trigger developers, adjust bug-priorities
- Beta testing
- Update documentation
- Pack RC and final version of FGDATA
- Create the RC and final version (source-tarball)
- Create the RC and final version for Linux
- Create the RC and final version for Windows
- Create the RC and final version for MacOS
- Distribute files to download servers
- Make adjustments on the web-site
- Announce the new version to the public
Open Items, Questions
- Can Hudson create binaries (RC) from the release branch?
- If not, how often will we create RC?