When a new branch is created, some work needs to be done to specify that the previous branch is no longer equivalent to HEAD.
Note: As srcbuild:
Edit /a/portbuild/conf/admin/admin.conf with the following changes:
Add new-branch to SRC_BRANCHES.
For what was previously head, change SRC_BRANCH_branch_SUBDIR to releng/branch.0 (literal zero).
Add SRC_BRANCH_new-branch_SUBDIR =head.
Run /a/portbuild/admin/scripts/updatesnap manually.
For each branch that will be supported, do the following:
As portbuild, kick-start the build for the branch with:
build create arch branch
As srcbuild, create bindist.tar.