LE-OS recipes.  Recipes and lists are licensed under 0BSD (LICENSE); the software they
build keeps its own licence (the `license` field).

  core/NAME/        one recipe per package: package.toml, build.sh, local sources
  lists/core-N.list build orders for the core releases (build-set.py)
  lists/bootstrap/  the pass1/pass2 lists that bootstrapped LE-OS from LFS

The directory a recipe lives in names the repository it is published to (core here,
as on ftp.passimit.com/core/x86_64/).  The architecture is not part of the path: one
recipe lists the architectures it builds for in its `arch` field.

Build a release:

  build-set.py lists/core-N.list --recipes core --db /srv/lpm/core/x86_64/core.db.tar.xz ...