b9132a6d

By: Michael Lynch <git@mtlynch.io>

Keep project-specific cache targets out of the shared build script

Run the optional upload hook without arguments so projects sharing the
build-all wrapper can choose their own upload targets. Let this project's
hook select checks.<system>.all and resolve its repository root so direct
invocations work from other directories.

Use linkFarm's package-set interface for the aggregate check. The pinned
nixpkgs produces the same derivation without mapping the attributes first.