Fedora uses a system of tracker bugs to keep track of freeze exception bugs - bugs which do not block a given milestone release (Alpha, Beta, Final), but which are considered high priority for tracking and fixing, and for which fixes may be accepted even during the freeze period for that release. This page defines the process by which bugs are proposed, reviewed and accepted as freeze exception bugs, and how freeze exception bugs are then tracked.
Note that freeze exception bugs used to be called nice-to-have or NTH bugs, and you may still find this name mentioned or used in old documentation and particularly in old bug reports.
See also the blocker bug process, which defines the similar process for blocker bugs - bugs that are blocking the release of its milestone releases and which must be fixed before these releases can proceed.
Or, when does this process affect me?
The process of nominating and reviewing freeze exception bugs is active to some degree at all times. It is particularly visible, however, after the Milestone freezes for each milestone of a release (Beta and Final). At the Milestone freeze (Beta freeze or Final freeze), the stable fedora package repository is frozen, meaning packages can no longer move from the updates-testing repository to the stable repository from which the 'candidate' composes are created.
If a Fedora milestone release is currently in a milestone freeze (you can check the schedule for the next release here) and you are a packager or tester and you believe a build of your package or a package you are testing should be in the milestone release, this process concerns you. After the milestone freeze, the build can only be promoted to 'stable' and included in the release if it fixes a bug that is granted blocker or freeze exception status.
After the milestone release is finished, the milestone freeze is lifted and builds can be marked as stable again without following this process, so if the build can wait until after the milestone release, you do not need to follow this process.
Freeze exception bug principles
Strict Fedora_Release_Criteria are used to define whether a bug should block a Fedora release, but determining whether a bug is worthy of a freeze exception is a more flexible process and should be done on a case-by-case basis. However, we have evolved some principles to be taken into account when evaluating a bug for freeze exception status.
In general, freeze exception bugs are usually bugs for which an update is not an optimal solution, and for which the fix is reasonably small and testable (this consideration becomes progressively more important as a release nears, so bugs may be downgraded from freeze exception status late in the release process if it transpires that the fix is complex and hard to test).
Types of bugs which are typically likely to be accepted as freeze exception bugs include:
- bugs which constitute infringements of the desktop-related Fedora_Release_Criteria as applied to non-default desktops
- bugs which result in a system being unable to reach a graphical environment
- significant installer bugs which do not meet the criteria to be blocker bugs
- bugs which constitute infringements of Fedora_Release_Criteria for secondary architectures will be presumed to be valid freeze exception bugs (unless there is a strong argument against, in a particular case)
Proposing freeze exception bugs
You can use the Blocker Bugs web application to propose a bug as a freeze exception. It will guide you through the process.
If you have an issue with the guided process or want to propose a freeze exception directly from Bugzilla for efficiency, you can use the manual process.
To propose a bug as a freeze exception for a release, mark it as blocking the tracker bug for freeze exception bugs in that release. To do this, enter the alias or bug ID of the tracker bug into the Blocks: field in Bugzilla. The aliases for the freeze exception tracker bugs follow a consistent naming scheme. For the next release, the Beta tracker will always be called BetaFreezeException, and the final release tracker will always be called FinalFreezeException. Rarely, you may need to propose a bug as a freeze exception for the next release but one - in this case, prepend FXX (where XX is the release number) to the name of the alias, e.g. F34BetaFreezeException. So, to mark a bug as a freeze exception for the release of Fedora 33 Beta, you would set it to block the bug BetaFreezeException. You can find a full list of tracker bugs at BugZappers/HouseKeeping/Trackers.
Reviewing freeze exception bugs
Proposed freeze exceptions are reviewed and either accepted or rejected as freeze exceptions in collaboration between three stakeholder groups: QA, Development and ReleaseEngineering. This is mostly done during weekly meetings for the express purpose of reviewing blocker and freeze exception bugs: the procedure followed during these meetings is documented here. FreezeException review meetings usually occur every Monday - immediately after the QA meeting - so long as there is at least one proposed blocker, but special review meetings can be scheduled at other times when necessary. They are always announced to the test-announce mailing list, which is CC'ed to devel. The freeze exception review meetings are public, and reporters who propose a bug as a freeze exception are allowed and indeed encouraged to attend the meeting where it is reviewed.
When appropriate, proposed freeze exceptions may also be reviewed between meetings by Bugzilla comment discussion, or during the engineering readiness meeting (also known as a go/no-go meeting) which is convened to decide whether a release candidate should be approved as a final release. In these cases, consensus between the three stakeholder groups should still be reached in order to accept or reject a bug as a freeze exception. However, review should not be done as part of QA meetings. If freeze exception review is required or desirable at the time of a QA meeting, a proper freeze exception bug review meeting should be convened immediately following the QA meeting.
Bugs that are accepted as freeze exceptions for the relevant release will be marked with the Whiteboard field. Bugs which are rejected as freeze exceptions will be updated to no longer block the relevant tracker bug, and have the Whiteboard field added so that if they are proposed as freeze exceptions again, it is clear they have already been considered and rejected. Therefore, a bug which has been proposed but not accepted or rejected can be identified by the lack of a relevant Whiteboard field. All changes to freeze exception status should also be documented with a comment. The comment should explain the rationale behind the decision and should link to the summary or logs of the meeting at which the decision was made.
Automatic freeze exceptions
Certain types of bugs are considered automatic freeze exceptions. These bugs can be marked as accepted by any member of one of the stakeholder groups without formal review. A comment should accompany this change, explaining that it has been made under the automatic freeze exception policy and linking to this section of this page. If anyone believes that a bug has been incorrectly marked as AcceptedFreezeException in this way, they may propose that it be formally reviewed by appending a comment to the bug or by raising it during a freeze exception review meeting. Only the following types of bug are considered automatic freeze exceptions.
- Bugs which entirely prevent the composition of one or more of the non-release-blocking images required to be built for a currently-pending (pre-)release
- Incorrect checksums present on any of the non-release-blocking TC/RC images (failures of QA:Testcase_Mediakit_ISO_Checksums)
- Unresolved dependencies on a non-release-blocking DVD-style (offline installer) image (failures of QA:Testcase_Mediakit_Repoclosure)
- File conflicts between two packages on a non-release-blocking DVD-style (offline installer) image without an explicit Conflicts: tag (failures of QA:Testcase_Mediakit_FileConflicts)
- Complete failure of any non-release-blocking TC/RC image to boot at all under any circumstance - "DOA" image (conditional failure is not an automatic freeze exception)
- Any non-release-blocking Beta or Final TC/RC image exceeding its maximum size (failures of QA:Testcase_Mediakit_ISO_Size)
- The default desktop background in a release-blocking desktop being the same as one of the last two stable releases
- AppStream updates (by FESCo vote)
No other type of bug can be considered an automatic freeze exception under any circumstance. In particular, "I think it is obviously a freeze exception" is not a valid reason to use this procedure. If you believe another type of bug should be added to the list, please propose the change on the test@ mailing list.
Tracking freeze exception bugs
Again, tracking freeze exception bugs and ensuring that they are fixed is a collaborative effort between the QA, Development and Release Engineering groups. The QA:SOP_Blocker_Bug_Meeting process includes reviewing the status of existing freeze exceptions and ensuring that the appropriate resources to fix them are in place, as well as evaluating proposed freeze exceptions.After blocker bugs, QA group members are encouraged to prioritize testing of freeze exception bug fixes, development group members are encouraged to prioritize developing fixes for freeze exception bugs, and release engineering group members are encouraged to prioritize the release of fixes for freeze exception bugs (after appropriate testing). Each group should have its own processes for ensuring its responsibilities in relation to freeze exception bugs are met.
In Bugzilla, freeze exception bugs should follow the normal workflow, with special attention paid by the development group to submitting proposed fixes to the updates-testing repository so they reach MODIFIED and ON_QA status, and special attention paid by the QA group to testing proposed fixes and setting ones that are tested successfully to the VERIFIED status.Builds that fix freeze exception bugs should be pulled into TC and RC builds by the release engineering team as long as they are submitted as proposed updates and meet the necessary karma requirements. No freeze exception bug should be set to CLOSED ERRATA until a fix is actually released to the stable repository for the release in question and also included in an RC compose (if it is related to a package from such a package set). If a working fix is added to a TC or RC build, but not yet pushed to the stable repository, the bug should not be marked CLOSED ERRATA, as this may result in the fix not being pushed to the stable repository and the fix accidentally omitted from the next candidate build as it is no longer possible to track the bug.