Recent stable Glibc releases are further maintained in so-called release branches, where they continue to receive backports of bugfixes committed to the main development branch (master). Thus, users will be able to get e.g. 2.11.1 with many bugfixes since fixed in mainline compared to the "main release" 2.11.
Current branches
Currently, these release branches are maintained:
General policy
Each release branch owns a Git ref namespace release/VERSION/, recommended structure being release/VERSION/master for development, while tags are made under the common scheme glibc-VERSION.REVISION (i.e. glibc-2.11.1).
Normally, a release branch is forked off master when the final stable version is tagged, and consists purely or almost purely of cherry-picked fixes committed to the master branch. Each branch is maintained by a single release manager, who has the responsibility of maintaining the particular stable branch, has final say on what goes in and tags further revisions on the branch. The branch is expected to receive many liberally merged bugfixes from master at the beginning when many new bugs are found, then become more conservative and decrease the rate of back-ports as most major problems are solved and the branch is being propagated to more mature distribution versions. Usually, the interested committers have discretion over which bugfixes to pick for back-porting, but if discussion arises, general consensus of the community is sought, the default choice being to err on the conservative side.
It should be noted that the decision when to make next stable release is fully in the hands of the main glibc maintainer (UlrichDrepper), only at that point some release manager volunteers (from the population of glibc hackers, generally) and starts maintaining the release branch. Each branch has so-called interested parties, usually glibc maintainers in distributions where the particular branch is being used; tagging revisions on the release branches should result of consensus between the maintainer and interested parties - one workable model is that the maintainer suggests that he wants to release and other people check if they are happy with the set of patches included and the timing is fine-tuned; if a release is important for one of the parties (e.g. distribution nearing a release), they can suggest a release of new revision as well if it is meaningful.
Anyone can suggest a fix committed on master (unless it's N/A for master for some reason - in that case, discussion about the patch is expected) to be included in a release branch, either by marking it by an appropriate keyword in bugzilla, or cherry-picking it themselves and sending a pull request. Developers with glibc commit permissions can in general push into any release branch, but they are expected to execute reasonable judgement and follow the branch policies. All cherry-picked commits should be created using git cherry-pick -x to indicate the id of the original commit in the commit message (see details on cherry-picking in Git). Always aim at having one cherry-picked commit for one original commit.
Note that the above process is still in flux and may change based on our experience with it. Particular release branches may fine-tune these policies in different ways, though the spirit should stay the same. Try to pay attention to what your past (or concurrent) predecessor release managers have done, and learn from their examples and mistakes. It is expected to have discussion on new policies (even per-branch ones) and any unusualities on libc-alpha.
Final words: Always keep in mind the GNU copyright discipline, and finally, Do not taunt Happy Fun Drepper.
Publishing
Here is a check-list to follow for release managers when tagging a revision release. Each release manager should have:
- [REQUIRED] A published (preferably well cross-signed) PGP key for signing the tag.
- [REQUIRED] Push access to git.sourceware.org; of course a release manager should already have that long before tagging a release.
- [RECOMMENDED] Have your PGP key in the list of glibc releasers on gnu.org; see below.
- [RECOMMENDED] Have full shell access to sourceware.org; see below.
When all is in place, to release a revision of the glibc branch:
- Create signed tag glibc-2.M.N and push it to the public glibc repository
Create the tag using git tag -s; verify it's signed by the PGP key you want to sign it with.
- The tag comment should contain something meaningful, e.g. the git shortlog of the changes since last release; ideally the full announcement you are about to send out as the last step.
- Create a tarball of the tagged release.
Use make dist in a build tree - it will generate couple of ../glibc*tar* files.
- Verify the tarballs are sensible, try to build the glibc from the tarball (e.g. using it as source for your distribution package).
- Sign + upload your tarball to ftp.gnu.org and sourceware.org - see below for a gnupload invocation that can make your life easier.
If you don't have full shell access on sourceware.org, get it from the overseers, referring to RolandMcGrath for acknowledge.
If you don't have PGP key on gnu.org, follow the GNU maintainer guide, again referring to RolandMcGrath for ack; you may also ask AlfredMSzmidt for help.
- Temporarily, the people listed above may help you with the uploads until you arrange the access.
- Update the glibc homepages at gnu.org and sourceware.org.
If you are clueless about the homepage git repository, ask CarlosODonell for help.
Send a mail with announcement to libc-alpha@sourceware.org, libc-announce@sourceware.org, and info-gnu@gnu.org.
Recommended contents is git shortlog output since the last release, prepended by some general description and possibly known problems list, and some kind of instructions on where to get the release.
You may use gnupload to easily sign and upload your tarballs:
gnupload --to ftp.gnu.org:glibc \
--to sources.redhat.com:~ftp/pub/glibc \
glibc-2.11.1.tar.gz glibc-2.11.1.tar.bz2 glibc-2.11.1.tar.xz