overlays/tvl: switch from https://github.com/tvlfyi/nix/ to nixpkgs-provided version (plus patches)

third_party/overlays/tvl.nix currently points to a custom cherry-picked-together branch (2.3-backport-await-users), with the build expression describing it as "with backports for build-user problems applied".

Having a separate tree is a bad idea for multiple reasons:

• It's hard to test changes to that branch without being able to push to github.com/tvlfyi/nix
• It's unclear which of these patches ended up upstream in the 2.3-maintenance branch (the commit messages don't contain pointers to PRs)

There already (and still) is a Nix 2.3 package expression in nixpkgs, and with plans to do a new point release containing some fixes, for example zstd decompression support, we really should be switching back to the nixpkgs 2.3, apply the patches on top (and try to upstream those that were never upstreamed).

1. We have

   • Escaping fix (needed for the Tvix test suite): https://github.com/NixOS/nix/pull/4012
   • Prevent failures when no build users are available: https://github.com/NixOS/nix/pull/3564
   • Fixes that keep release.nix working with nixpkgs:
     • https://github.com/tvlfyi/nix/commit/4510dbc8a6802902cbab6444134659548fffb9b0
     • https://github.com/tvlfyi/nix/commit/46a91f2abaee85135cbb447c13957d3c5e9091a9

   sterni at 2023-10-29T10·31+00

2. The build users fix is the most important, because without it we can not build channel bumps without manually intervening to restart parts of the builds constantly.

   tazjin at 2023-10-30T05·32+00

3. Sent backport PR for 4012 in https://github.com/NixOS/nix/pull/9260.

   Sent backport PR for 3564 in https://github.com/NixOS/nix/pull/9261.

   flokli at 2023-10-31T10·19+00

4. pkg-config rename sent in https://github.com/NixOS/nix/pull/9262. unstringlify configure flags sent in https://github.com/NixOS/nix/pull/9263.

   flokli at 2023-10-31T10·26+00

5. All PRs got merged, https://cl.tvl.fyi/c/depot/+/9906 switches this back to the upstream branch (bringing in zstd support too, yay)

   flokli at 2023-11-03T08·48+00

6. tazjin closed this issue at 2023-11-27T22·08+00