# usages:
#
-# git-debrebase [<options>] new-upstream-v0 \
-# <new-version> [<orig-commitish> \
-# [<extra-orig-name> <extra-orig-commitish> ...] \
-# [<git-rebase options>...]]
-#
-# git-debrebase [<options> --] [<git-rebase options...>]
-# git-debrebase [<options>] analyse
-# git-debrebase [<options>] breakwater # prints breakwater tip only
-# git-debrebase [<options>] stitch [--prose=<for commit message>]
-# git-debrebase [<options>] launder-v0 # prints breakwater tip etc.
# git-debrebase [<options>] downstream-rebase-launder-v0 # experimental
-#
-# git-debrebase [<options>] convert-from-gbp [<upstream-git-rev>]
-# git-debrebase [<options>] convert-to-gbp
# problems / outstanding questions:
#