This is perfect. Thanks a ton! I did notice that the lock didn’t update when changing the revision, so perhaps this is a bug.
edit
Unfortunately, this doesn’t actually solve the problem, it pushes the error down the chain. After actually attempting to use them from within my configuration I get the following error:
41| else if info.type == "path" then
42| { outPath = builtins.path { path = info.path; };
| ^
43| narHash = info.narHash;
string './pkgs' doesn't represent an absolute path
Related
https://github.com/NixOS/nix/issues/4218
https://github.com/NixOS/nix/issues/3978