Comment 8 for bug 1713549

While I realize that building HEAD is less obvious I think it is the right thing to do.
I think it builds the right habits and then ultimately makes you *less* likely to lose things, because you're committing them to git. Even if a user resorts to something like:
  git commit -a -m "" && git ubuntu build-package

I often end up with files that are in my tree from general development, things like 'out.diff' from 'git diff > out.diff' and such. building HEAD allows you to not care.

I guess another option would be:
  git build-package tree
  git build-package HEAD
  git build-package commitish

the special 'tree', which could even be the default would build working-tree.
All others would/could use worktree to create a temporary and clean directory and build there.