Subject: Working on a cvs branch
Date: Thu, 03 Dec 1998 19:57:00 -0600
From: Alan M Jonckheere <Jonckheere@fnal.gov>
Organization: Fermi National Accelerator Laboratory
To: Don Coppage <dlc@fnal.gov>
CC: D0 Release Mgr <d0-release-mgr@fnal.gov>, d0rug@fnal.gov

Working on a cvs branch is really simple until you try to merge the
branch back in. I do *not* recommend that you do that. Instead, make any
changes twice, once in the branch, once in the mainline.

1) chose your branch point. This should already have been rtagged.
2) cvs rtag -b -r <existing tag> <branch tag> <package>
   <branch tag> should be of the form: <existing tag>-branch (or -br)
3) newrel -t <base-rel> <mytest-branch> as usual to create a new working
area. Good idea to name the subdirectory something with "branch" in the
name.
4) cd <mytest-branch>
5) addpkg <package> <branch tag>
   NOTE: no <branch tag> takes the place of "-h", do *not* use -h
6) the rest is *exactly* what you aways do EXCEPT
7) to tag a new version on the *branch*
   cvs rtag -r <branch tag> <new tag> <package>

step 5) checks out the version of <package> at the base of the branch
since this is the 1st time it's been done. Later, the same addpkg will
check out the *head* of the branch. The key is that *any* -r <branch
tag> always refers to the head of the branch labeled <branch tag>. Thus
a branch tag (created via rtag -b) is fundamentally different than a
normal tag created without the -b although the command syntax is exactly
the same in the two case. That's why we add the -r ... in step 7). It
refers to the *head* of branch <branch tag>

In step 6) you use update, commit etc *exactly* as you do on the
mainline. You just update from and commit to the head of the branch
rather than the mainline head.

The only caviot is that I'm not super sure what adds and removes do on a
branch. If you *must* do either to a branch, give me a call first and
I'll run some tests.

To make changes to *both* the branch and the head, have *two* working
directories and be careful to put the correct edits into each.

No problem.

Alan

Don Coppage wrote:
>
> Hi,
>
>    It turns out I need to learn how to make branch revisions for another
> package as well, but I'm a little intimidated by the extent of the cvs
manual
> instructions. Could someone possibly give me a safe sequence of commands?
>
> Thanks,
> Don
>
> On Thu, 3 Dec 1998, Paul Russo wrote:
>
> > Don,
> >
> > I can't grab pieces of packages for the build.
> >
> > However you could make a branch revison with the corrections for this
> > release.
> >
> > Paul S. Russo
> > d0-release-mgr@fnal.gov
> >