╭─whovian@nixos-wsl /tmp/wat/nix
╰─$  nix log /nix/store/9xi552907cas1y8rfwyifai5c7h92sjd-dotnet-vmr-10.0.0-preview.6.drv | rg -i "Phase com"
unpackPhase completed in 2 minutes 56 seconds
configurePhase completed in 59 seconds
buildPhase completed in 1 hours 50 minutes 18 seconds
installPhase completed in 43 seconds
fixupPhase completed in 2 minutes 50 seconds

So it took 2 hours but dotnetCorePackages.dotnet_10.vmr built! \o/

Oh no, it's not.

$  PAGER= nix log /nix/store/hipsbwjbxwlw20sjpmsfgkz0s7ja90fn-Aaru-6.0.0.drv
Running phase: unpackPhase
@nix { "action": "setPhase", "phase": "unpackPhase" }
unpacking source archive /nix/store/1xzm3a5wx770b9wcn1ffl6hqy7v7la1i-source
source root is source
Running phase: patchPhase
@nix { "action": "setPhase", "phase": "patchPhase" }
Running phase: configureNuget
@nix { "action": "setPhase", "phase": "configureNuget" }
The command could not be loaded, possibly because:
  * You intended to execute a .NET application:
      The application 'new' does not exist or is not a managed .dll or .exe.
  * You intended to execute a .NET SDK command:
      A compatible .NET SDK was not found.

Requested SDK version: 10.0.100-preview.7
global.json file: /build/source/global.json

Installed SDKs:
10.0.100-preview.6.25358.103 [/nix/store/k0z0ayma9s53pmplr9770zid9z9c0x9y-dotnet-sdk-10.0.100-preview.6.25358.103/share/dotnet/sdk]

Install the [10.0.100-preview.7] .NET SDK or update [/build/source/global.json] to match an installed SDK.

Learn about SDK resolution:
https://aka.ms/dotnet/sdk-not-found

I can probably just remove the global.json and it'll likely work fine, but that still isn't fun.

In this case it would be a fall back, but thank ya. It's something that I'll check later.

$ cat global.json

{
  "sdk": {
    "version": "10.0.100-preview.7",
    "rollForward": "latestFeature",
    "allowPrerelease": true
  }
}

Sorry, those are basically two different errors.

The original error was NU1101 ("error NU1101: Unable to find package NAME. No packages exist with this id in source(s): nuget, _nix") for Kaligraphy, Kanvas, Kompression, and Komponent.

CS0246 is from me trying to self-package Komponent, Kaligraphy, and Kanvas to provide the derivation.
(k2Repo in the following is just me trying to set the used src once in flake.nix and passing it to the derivations that way so I don't have to update the used commit info more than once)

{
  packages.x86_64-linux = {
    default = pkgs.callPackage ./package.nix { inherit k2Repo; komponent = self.packages.${system}.komponent; kaligraphy = self.packages.${system}.kaligraphy; kanvas = self.packages.${system}.kanvas; };
    komponent = pkgs.callPackage ./komponent.nix { inherit k2Repo; };
    kaligraphy = pkgs.callPackage ./kaligraphy.nix { inherit k2Repo; komponent = self.packages.${system}.komponent; };
    kanvas = pkgs.callPackage ./kanvas.nix { inherit k2Repo; komponent = self.packages.${system}.komponent; };
  };
};