Unforeseen problem: `buildkite-agent` runs its builds in a separate directory,
so if I want the `nix-build` command to build the newly checked out code, I need
to set <briefcase> to the CWD.
I've encountered a few problems with attempting to support nixos-rebuild:
- the activation step requires `sudo` privileges
- the `buildkite-agent` runs on the same machine, socrates, that is rebuilding
itself. This means that when the activation step runs, it will attempt to
restart `buildkite-agent` when the agent is still working
I'm slowly removing places in my nix code that rely on '<bracket>' notation, so
that I no longer depend on NIX_PATH being set. I still have more work to do.
{covid-uk,sandbox}/default.nix are breaking when I attempt to run my
build-socrates.sh script locally, so I'm temporarily disabling them until I can
get CI working as I expect.