Co-authored-by: Graham Christensen <graham@grahamc.com>
... but just fixing up merge conflicts from the introduction of flakes
and the removal of the Jobs table.
This is a breaking change. Previously, packages named `packageset.foo`
would be exposed in the fake derivation channel as `packageset-foo`.
Presumably this was done to avoid needing to track attribute sets, and
to avoid the complexity. I think this now correctly handles the
complexity and properly mirrors the input expressions layout.
Previously, the build ID would never flow through channels which
exited.
This patch tracks the buildOne state as part of State and exits avoids
waiting forever for new work.
The code around buildOnly is a bit rough, making this a bit weird to
implement but since it is only used for testing the value of improving
it on its own is a bit questionable.
A reproduce script includes a logline that may resemble:
> using these flags: --arg nixpkgs { outPath = /tmp/build-137689173/nixpkgs/source; rev = "fdc872fa200a32456f12cc849d33b1fdbd6a933c"; shortRev = "fdc872f"; revCount = 273100; } -I nixpkgs=/tmp/build-137689173/nixpkgs/source --arg officialRelease false --option extra-binary-caches https://hydra.nixos.org/ --option system x86_64-linux /tmp/build-137689173/nixpkgs/source/pkgs/top-level/release.nix -A
These are passed along to nix-build and that's fine and dandy, but you can't just copy-paste this as is, as the `{}` introduces a syntax error and the value accompanying `-A` is `''`.
A very naive approach is to just `printf "%q"` the individual args, which makes them safe to copy-paste. Unfortunately, this looks awful due to the liberal usage of slashes:
```
$ printf "%q" '{ outPath = /tmp/build-137689173/nixpkgs/source; rev = "fdc872fa200a32456f12cc849d33b1fdbd6a933c"; shortRev = "fdc872f"; revCount = 273100; }'
\{\ outPath\ =\ /tmp/build-137689173/nixpkgs/source\;\ rev\ =\ \"fdc872fa200a32456f12cc849d33b1fdbd6a933c\"\;\ shortRev\ =\ \"fdc872f\"\;\ revCount\ =\ 273100\;\ \}
```
Alternatively, if we just use `set -x` before we execute nix-build, we'll get the whole invocation in a friendly, copy-pastable format that nicely displays `{}`-enclosed content and preserves the empty arg following `-A`:
```
running nix-build...
using this invocation:
+ nix-build --arg nixpkgs '{ outPath = /tmp/build-138165173/nixpkgs/source; rev = "e0e4484f2c028d2269f5ebad0660a51bbe46caa4"; shortRev = "e0e4484"; revCount = 274008; }' -I nixpkgs=/tmp/build-138165173/nixpkgs/source --arg officialRelease false --option extra-binary-caches https://hydra.nixos.org/ --option system x86_64-linux /tmp/build-138165173/nixpkgs/source/pkgs/top-level/release.nix -A ''
```
