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 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 and Checklist
- Dec/Jun 17th: Development stream is declared "frozen" or "yellow".
- Send a mail to the flightgear-devel mailing-list to announce the state.
- Jan/Jul 17th: Create new release branch, assign new version number to dev-stream, re-open streams
- Send a mail to the flightgear-devel mail-list, asking not to commit/push anything, declare the streams "closed" or "red"
- Bump up the version-number of simgear/next, flightgear/next and fgdata/master to an even number (2.3.0 -> 2.4.0)
- Compile and test drive FlightGear with the new version-number
- Commit the new version number to next (flightgear+simgear) and master(fgdata)
- Tag (annotated) flightgear, simgear and fgdata with "version/2.4.0"
- git tag -a version/2.4.0 (Enter a wise comment)
- Create the release branches on simgear, flightgear and fgdata named release/2.4.0
- git branch release/2.4.0
- On the next/master branches, bump up the version-number of simgear, flightgear and fgdata to an odd number (2.4.0 -> 2.5.0)
- Compile and test drive FlightGear with the new development version number
- Commit the changes of version-number to next/master
- Tag (annotated) flightgear, simgear and fgdata with "version/2.5.0"
- git tag -a version/2.5.0 (Enter a wise comment)
- Push the branches next/master and release/2.4.0 and the tags upstream
- for flighgear, simgear and fgdata: git push origin release/2.4.0
- for flighgear, simgear and fgdata: git push origin version/2.4.0
- for flighgear, simgear and fgdata: git push origin version/2.5.0
- for flightgear and simgear: git push origin next
- for fgdata: git push origin master
- declare dev-streams "open" or "green"
- Send a mail to the flightgear-devel mailing-list to announce the state.
- Trigger James for the Jenkins-builds and Curt for a snapshot release
- Feb/Aug 17th: Create binaries/installers, pack fgdata, publish files, announce new version, close the release-branch
- Tag the release/2.4.0 branches of simgear, flightgear and fgdata.
- Merge the branch release/2.4.0 into master (NOT next) for flightgear and simgear
- We don't have a next branch for fgdata, no merging of the release branch here.
Definition of Stream States
- Normal development of the code base and fgdata. Unrestricted (well, sort of) access to the streams. This state lasts for five month after the release branches were created.
- No new features or major changes shall be pushed onto the development streams (neither source nor data). This period is for preparing the code for the release and make sure there are no major issues. It lasts for four weeks until creation of the release branches.
- Nothing shall be pushed to the development streams (simgear, flightgear and fgdata). This state is for creating the release branches. It lasts for just a few hours on Jan 17th and Jul 17th around 12:00 UTC.
Bug fix committing policy
Fixes for bugs during the shakedown test of the release branch may be applied to the branches next or release/2.4.0. A fix goes into release/2.4.0 if the development of next has moved forward and this fix does not apply there. It also goes into the release branch if there will be a better fix for next. A fix goes into next if it is also solves an issue for the next version. Cherry-pick this commit into the release/2.4.0 branch.
DO NOT merge next into release/2.4.0 or vice versa. Most likely, there will be commits that are not welcome in or even break the other branch.
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: FAQ, GetStart, wiki
- 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
- Collect/make screenshots for the gallery
- Announce the new version to the public
- Write a changelog: Changelog 2.4.0
- Contact flightsim websites and send them/link them to a "press release"
Open Items, Questions
Can Jenkins create binaries (RC) from the release branch?Binaries: yes, installers: semiautomatic (Curt & Tat)
If not, how often will we create RC?Weekly
- Surely the beta testing rôle could/should be undertaken by selected members the community - selected based on their ability to write clearly and to write usefully. (computer specifications, errors from the console, and other pieces of useful objective information - no subjective rot such as "it doesn't work")
- Surely not! The more people beta-test our release candidates, the better.