Use Nix in CircleCI

[domenkozar]

I see https://github.com/mtlynch/whatgotdone/blob/master/flake.nix#L14: see https://zimbatm.com/notes/1000-instances-of-nixpkgs

[mtlynch]

@domenkozar - Thanks, I'm still pretty new to Nix, so I didn't realize that was creating overhead. I tried revising it based on that article:

https://github.com/mtlynch/whatgotdone/blob/63ea6b573d070554fcaf7e0b0325dec572c6cb48/flake.nix

Is there any way around creating multiple instances of nixpkgs if I'm pinning versions that aren't all available from the same nixpkg version?

[domenkozar]

@domenkozar - Thanks, I'm still pretty new to Nix, so I didn't realize that was creating overhead. I tried revising it based on that article:

https://github.com/mtlynch/whatgotdone/blob/63ea6b573d070554fcaf7e0b0325dec572c6cb48/flake.nix

Is there any way around creating multiple instances of nixpkgs if I'm pinning versions that aren't all available from the same nixpkg version?

I see you have two of the same commit, so you can get rid of that and probably gain a few seconds.

90s is still a lot, it shouldn't take that long. Are those CircleCI runners that slow?

Note that for each nixpkgs, it has to download 100M file, unpack it to over GB and import it (which is a lot of files).