Release plan
Current release: 2020.3.19 (18 Oct 2023) Next release: 2020.3.20 See release plan for details. |
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 edit this page. In particular, improvements should be based on Release plan#Lessons learned from past releases. Please discuss this concept at the mailing-list.
General release concept
New FlightGear releases are 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 not a prime, 7 is a prime and so is 17). On the 17th of January (1) and July (7) a new release branch is created for SimGear, FlightGear and FGDATA.
After branching, there is one month for bug fixing in the release branch, so building and packing of the binaries and FGDATA takes 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 is 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 should not add any new features, subsystems, and the like. 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.
Version numbers
FlightGear version numbers exist of three digits, seperated by dots:
- Major (2.4.1): is only increased after significant changes to the functionality of the software, i.e. 1.X.X => 2.0.0 (due to switch to OSG).
- Minor (2.4.1): has two applications:
- Stable releases always have even numbers, i.e. 2.6.0, 2.8.0, 3.0.0.
- The development stream (latest Git version) uses an odd number, increasing the minor number of the latest stable release's version by one. I.e., when the latest release is 2.8.0, the current development stream is 2.9.0.
- Revision (2.4.1): is increased by bugfix releases, i.e. 2.8.1, 2.8.2, 2.8.3.
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
- Create a "release preperations" topic at the forum and make it a "Global Announcement"
- Change the content of wiki template at Template:GitStatus to
{{GitStatus:frozen}}
- Bump up the version-number of simgear/next, flightgear/next and fgdata/master to an even number (2.9.0 -> 3.0.0)
- modify options.cxx to bump the hard-coded base package version number in [1]
- 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/3.0.0
- git tag -a version/3.0.0 (Enter a wise comment)
- Push the branches next/master and the tags upstream
- for flightgear and simgear: git push origin next
- for fgdata: git push origin master
- for the tags (all repos): git push origin version/3.0.0
- Jan/Jul 17th: Create new release branch, assign new version number to dev-stream, re-open streams
- Pull current Git, create the release branches (for sg/fg/fgdata):
- git pull
- git branch release/3.0.0
- On the next/master branches, bump up the version-number of simgear, flightgear and fgdata to an odd number (3.0.0 -> 3.1.0)
- 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/2.9.0"
- git tag -a version/2.9.0 (Enter a wise comment)
- Push the branches next/master and release/3.0.0 and the tags upstream
- for flightgear, simgear and fgdata: git push origin release/3.0.0
- for flightgear and simgear: git push origin next
- for fgdata: git push origin master
- for the tags (all repos): git push origin version/3.1.0
- Declare dev-streams "open" or "green"
- Ask a wiki admin to change the content of wiki template at Template:GitStatus to
{{GitStatus:open}}
- Send a mail to the flightgear-devel mailing-list to announce the state.
- Ask a wiki admin to change the content of wiki template at Template:GitStatus to
- Trigger James for the Jenkins-builds and Curt for a snapshot release and ThorstenB for the OpenSuse build
- Pull current Git, create the release branches (for sg/fg/fgdata):
- Feb/Aug 1st: Start preparing the release notes and a press announcement
- Feb/Aug 17th: Create binaries/installers, pack fgdata, publish files, announce new version, close the release-branch.
- Generate latest getstart.pdf, push the PDF to fgdata/master - and cherry-pick to the release branch. Generate latest getstart HTML, push PDF and HTML to the MapServer site.
- Tag the release/3.00 branches of simgear, flightgear and fgdata and push the tags.
- for flighgear, simgear and fgdata: git tag version/3.0.0-final
- for flighgear, simgear and fgdata: git push origin version/3.0.0-final
- Merge the branch release/3.0.0 into master (NOT next) for flightgear and simgear and push the branch
- We don't have a next branch for fgdata, no merging of the release branch here.
- for flighgear and simgear:
- git checkout -b master origin/master or git checkout master if you already have the local branch
- git merge version/3.0.0-final
- git push origin master
- Core developers and other contributors should be invited to add their release related experiences (i.e. suggestions for improvements) to the wiki to help update and improve the release plan (i.e. this page) accordingly.
To bump up the version number
- fgdata
- edit the version file
- SimGear
- edit the version file
- FlightGear
- edit the version file
Definition of repository states
Bug fix committing policy
Fixes for bugs during the shakedown test of the release branch may be applied to the branches next or release/2.8.0. A fix goes into release/2.8.0 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/2.8.0 branch.
DO NOT merge next into release/2.8.0 or vice versa. Most likely, there will be commits that are not welcome in or even break the other branch.
Bug tracking
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.
Bugs that were present in the latest stable release, and now considered "fixed", should be assigned a milestone label, corresponding with the upcoming stable release number. By doing so, they'll end up in the list of fixed bugs.
Tasks and owners
Task | Owner(s) | |
---|---|---|
Announce the state-change of the dev-streams | TorstenD | |
Create/maintain the git branches | TorstenD | |
Track the bugs on the tracker, trigger developers, adjust bug-priorities | ThorstenB, Gijs, James, ... | |
Beta testing | EVERYBODY | |
Update documentation: FAQ, The Manual, wiki | Stuart, Gijs and anyone else | |
Pack RC and final version of FGDATA | ||
Create the RC and final version | Source-tarball | Curt |
Linux | ThorstenB (for openSUSE) | |
Windows | Curt | |
MacOS | Tat | |
Distribute files to download servers | Curt | |
Make adjustments on the web-site | Collect/make screenshots for the gallery | Curt |
Generate aircraft page | Curt, Gijs | |
Announce the new version to the public | Write a changelog: Changelog 3.0.0 | All developers |
Contact flightsim websites and send them/link them to the "press announcement". See release promotion for a list of already-contacted and yet-to-contact websites/magazins. | EVERYBODY |
Open items, questions
- Automate the creation of Windows and Mac installers
- Automate the creation of FGDATA distribution
- Possibly try to find a way to automate testing of updated jsbsim code, so that the chance for breakage is reduced by running scripted tests [2]
Lessons learned
This is a list of lessons learned from the previous releases, things that turned out well and should be kept for the next release as well as thing that didn't turn out so well and should be changed for future releases. Ideally, the release plan should be updated and augmented so that the lessons learned are incorporated accordingly.
3.2
(not yet released)
3.0
(not yet released)
2.11
(not yet released)
2.10
- perform a sync with JSBSim sources before the feature freeze.
- GLSL shaders and effects should be treated like core code, and should be tested on different platforms (NVIDIA, ATI/AMD, Intel) [3]
- New/updated Nasal scripts contributed to the base package should be checked to properly support important features like simulator reset, this also applies to Nasal scripts used by aircraft [4]
- there were a number of navcache/SQLite related issues reported via the issue tracker and the forum/devel list [5]
2.8
- Lack of stress-testing: A number of users reported severe memory growth issues (with fgfs consuming as much as 14gb of RAM), many directly related to new features, such as random buildings: [6] [7] [8] [9] These could have probably been identified earlier by running FG for extended periods of time, and testing the shipped aircraft with the default KSFO scenery, and new features such as random buildings enabled.
- Lack of graceful feature scaling: Several users with old graphics cards reported not being able to run FG 2.8 without crashing during startup, because the FG defaults didn't scale for old hardware [10]
- According to noaa.gov it seems that the NOAA metar source got phased out in 04/2012 and moved to a new URL[11], some users reported issues related to this[12]. However, the metar URL is currently hard-coded in the fgfs/metar source code - in addition, the default format is no longer a plain text dump [13]. It would make sense to make the URL a string property that can be put into preferences.xml and then use a Nasal listener to parse the resulting XML/HTML and set a plain text property instead, that can be processed by the existing metar code.
- Broken OSX downloads
- the OSX 10.8 release and code signing caused some irritation
- After the 2.8 release a number of users on the forums reported seeing GLSL related errors, because some of the 2.8 shaders used GLSL features only supported by more recent GLSL compilers/drivers - it would probably make sense to test all shader settings on all 3 platforms and check if they cause any errors (and "backport" shaders as necessary). Apple/Mac OSX seems to be more problematic
- Microsoft Redistributables were apparently not shipped with the Windows installer ?
- The changelog should be written as early as possible
- The code freeze could probably be lifted for patches that are not normally enabled/used by any default code paths (or shipped aircraft) in a FlightGear release. This probably involves Nasal extension functions, fgcommands, telnet commands, but also custom hard coded instruments or instrumentation-related APIs (think Canvas). Basically, whenever there's no chance to break a release by committing a certain patch, because the code path will not be executed by default without explicitly enabling it. For 2.8, this also meant that the Nasal Canvas API could not be included due to the code freeze, which however wasn't used by any systems or aircraft - so that there would have been zero chance for breakage [14] [15].
- The wiki contains a number of resources to help new users with hardware decisions, such as Hardware Recommendations Notebooks known to run FlightGear and Supported Video Cards - these should probably be updated for each release several weeks in advance.
2.6
- feature freeze in general
- helped a lot during release management. Kept the commit traffic low and thus helped identifying those commits required to pick into the release.
- feature freeze for aircraft
- Technically, a feature freeze for aircraft is not necessary as long as this aircraft is not part of the base distribution and no common parts are affected. If it's guaranteed that the changes remain in FGDATA/Aircraft/MyAircraft and no other files are touched, these updates should be OK up to shortly before the release.
- switching to a new version of supporting libraries like OSG.
- The move to OSG 3.x introduced some major issues. If at all possible, switch to a new library early in the development cycle.
- manual creation of release candidates and the release binaries
- It's preferable to have equal numbers for release candidates for all O/S and probably a git-tag for each candidate.
- release date/time frame
- It took several days to release all the subparts. Might be better to upload all files and pages to hidden folders and publish them all at once (or at least within a couple of hours). That'll have several advantages:
- no big difference between releases for the various OS.
- the website will switch to the new release state quickly. With 2.6.0, the aircraft page was published before the setup. The release announcement was published even later.
- It took several days to release all the subparts. Might be better to upload all files and pages to hidden folders and publish them all at once (or at least within a couple of hours). That'll have several advantages: