This is even useful for local development, as you can pre-populate the
binary cache before running CI (assuming you have the token). Also, it
being in a script makes it easier to test.
We've added attic as a flake input even though the flake itself doesn't
use it so that we can use `--inputs-from .` in Nix commands to reference
a locked version of attic. This helps with reproducibility and caching,
and to makes it easy to update attic because it's part of the normal
flake lifecycle.
`nixos-unstable` is the rolling release channel of NixOS. The default is
the master branch, which doesn't always have a populated binary cache
and so may result in compiling a bunch of stuff unnecessarily.
Also add `.envrc` for direnv + Nix users. This makes developing locally
easier for us NixOS folks.
The flake itself will allow NixOS users to pull code directly from
Conduit's repository, making it completely trivial to stay up-to-date
with every commit.
I'd also like to add a NixOS module directly to this repository at some
point so that new configuration options will be available in the NixOS
module faster. But for now, NixOS users can simply override
`serivces.matrix-conduit.package` and get pretty much all the
functionality.
I've added myself to the `CODEOWNERS` file for the Nix files, since I am
willing to maintain this stuff. I use Conduit on NixOS so I'm personally
invested in having this work.
Lastly, `.gitignore` was updated to exclude symlinks created by `direnv`
and `nix build` and other such Nix commands.
This doesn't come without maintenance burden, however:
* The `sha256` in `flake.nix` will need to be updated whenever Conduit's
MSRV is updated, but that should be pretty infrequent.
* `nix flake update` should be run every so often to pull in updates to
`nixpkgs` and other flake inputs. I think downstream users can also
override this themselves with `inputs.<name>.inputs.<name>.follows`.
* `nix flake check` should be run in CI to ensure Nix builds keep
working.
* `nixpkgs-fmt --check $(fd '\.nix')` (or similar) should be run in CI
to ensure style uniformity.
