for some reason the src override isn't effective and it still (eagerly?) evaluates the selectSystem function in losgeq.nix:

       … while calling the 'throw' builtin
         at /nix/store/idq1bmwwy9rlkc21hccvx42wlwpxsx1f-source/pkgs/by-name/lo/logseq/package.nix:20:45:
           19|   inherit (stdenv.hostPlatform) system;
           20|   selectSystem = attrs: attrs.${system} or (throw "Unsupported system: ${system}");
             |                                             ^
           21|   suffix = selectSystem {

       error: Unsupported system: aarch64-linux