Command 'nix eval .#homeConfigurations --apply builtins.attrNames --json' failed with exit code 1.
Standard err was:


warning: ignoring untrusted flake configuration setting 'allow-import-from-derivation'.
Pass '--accept-flake-config' to trust it
warning: ignoring untrusted flake configuration setting 'extra-substituters'.
Pass '--accept-flake-config' to trust it
warning: ignoring untrusted flake configuration setting 'extra-trusted-public-keys'.
Pass '--accept-flake-config' to trust it
trace: WARNING: No sha256 found for source-repository-package https://github.com/IntersectMBO/cardano-api ref=(unspecified) rev=4ab850fcdefe8536fb98274ba5eaf54030a852e8 download may fail in restricted mode (hydra)
error:
       … while calling the 'head' builtin

         at /nix/store/g2ysyzdx76m4z7lnmyddcwdz25lx7kn1-source/lib/attrsets.nix:1575:11:

         1574|         || pred here (elemAt values 1) (head values) then
         1575|           head values
             |           ^
         1576|         else

       … in the left operand of the update (//) operator

         at /nix/store/0wvkjzrr92b5x8gp5al49l96vjxzb3qk-source/lib/default.nix:403:29:

          402|         else
          403|           (b.${name} or {}) // (a.${name} or {});
             |                             ^
          404|     }) (__attrNames (a // b)));

       (stack trace truncated; use '--show-trace' to show the full trace)

       error: fetchTree argument 'ref' is null while a string, Boolean or integer is expected