When some pull request is committed in an old release, this does not get propagated in the subsequent one, apart from specific cases (e.g. THREADED builds).
In order to understand what is missing one can use the git log command, where the most recent release is the beginning of the log and the previous one is the end of the log. E.g.:
git fetch official-cmssw git log --reverse --first-parent --topo-order official-cmssw/CMSSW_7_3_X..official-cmssw/CMSSW_7_2_X
will show the merged pull requests which are part of
CMSSW_7_2_X but not of
CMSSW_7_3_X. In order to merge a few of them, the best strategy is:
git fetch official-cmssw ; git reset --hard official-cmssw/CMSSW_7_3_X.
git merge <commit>to merge that pull request and all those preceding it.
git push my-cmssw HEAD:forward-port-CMSSW_7_3_X
Variations for this include using a different merge strategy (e.g.
when merging so that in case of conflict ours (i.e. the newest branch) side of
the conflict is preferred (you can also use
If you wish to ignore one or more PR, you can use:
git merge -s ours <commit>
which will discard all the pull request up to
Notice also that while you can do the merge incrementally, you should always do it in order.
Find below a web based view of what is missing to be forward ported for the various releases.
The script auto-update-git-branches automatically forward ports the changes between some cmssw and cmsdist branches. You can see the script to know which branches are currenly being forward ported automatially. It is run by update-github-pages
Sometimes a pull request is merged in a branch and should not be merged into others. For example, #8480 was merged in CMSSW_7_5_X, but these changes should not be merged to CMSSW_7_5_ROOT5_X. The next time update-github-pages runs, it will merge those unwanted changes.
In order to prevent a pull request for being forward ported into another branch you can do the following:
git clone firstname.lastname@example.org:cms-sw/cmssw.git git remote add my_clone \<url\> git remote add pr_repo \<url\>
git checkout -b avoid-merge origin/unwanted_receiving_branch
git merge -s ours pr_repo/pr_branch_name
git push my_clone HEAD:avoid-merge