guest agent connection lost: nix config build failed: exit=1 error=None output=unpacking 'github:nixos/nixpkgs/f4a03c008967841f2a0b3cb7c436fc6fc31671f6' into the Git cache... error: … while calling the 'derivationStrict' builtin at «nix-internal»/derivation-internal.nix:37:12: 36| 37| strict = derivationStrict drvAttrs; | ^ 38| … while evaluating derivation 'nixos-system-spindle-microvm-26.05pre-git' whose name attribute is located at /nix/store/bmwp8va0bazc5v3vybl00nm1p9z9ah56-9figz32vbiblaw5x3li1hc8q9qwlwf27-source/pkgs/stdenv/generic/make-derivation.nix:647:11 … while evaluating attribute 'buildCommand' of derivation 'nixos-system-spindle-microvm-26.05pre-git' at /nix/store/bmwp8va0bazc5v3vybl00nm1p9z9ah56-9figz32vbiblaw5x3li1hc8q9qwlwf27-source/nixos/modules/system/activation/top-level.nix:63:7: 62| allowSubstitutes = false; …