capnp compile std failed

flake.nix

{                                                                                                                                                                                                                                                                                                            
  description = "bump rockets, make whoosh";                                                                                                                                                                                                                                                                 
                                                                                                                                                                                                                                                                                                             
  inputs = {                                                                                                                                                                                                                                                                                                 
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";                                                                                                                                                                                                                                                   
    templ.url = "github:a-h/templ";                                                                                                                                                                                                                                                                          
  };                                                                                                                                                                                                                                                                                                         
                                                                                                                                                                                                                                                                                                             
  outputs = { self, nixpkgs, templ, ... }:                                                                                                                                                                                                                                                                   
    let                                                                                                                                                                                                                                                                                                      
      supportedSystems = [ "x86_64-linux" "x86_64-darwin" "aarch64-linux" "aarch64-darwin" ];                                                                                                                                                                                                                
                                                                                                                                                                                                                                                                                                             
      forAllSystems = nixpkgs.lib.genAttrs supportedSystems;                                                                                                                                                                                                                                                 
                                                                                                                                                                                                                                                                                                             
      nixpkgsFor = forAllSystems (system: import nixpkgs { inherit system; });                                                                                                                                                                                                                               
    in                                                                                                                                                                                                                                                                                                       
    {                                                                                                                                                                                                                                                                                                        
      packages = forAllSystems (system:                                                                                                                                                                                                                                                                      
        let                                                                                                                                                                                                                                                                                                  
          pkgs = nixpkgsFor.${system};                                                                                                                                                                                                                                                                       
          go-capnp = pkgs.fetchFromGitHub {                                                                                                                                                                                                                                                                  
            name = "go-capnp";                                                                                                                                                                                                                                                                               
            owner = "capnproto";                                                                                                                                                                                                                                                                             
            repo = "go-capnp";                                                                                                                                                                                                                                                                               
            rev = "main";                                                                                                                                                                                                                                                                                    
            hash = "sha256-P6YP5b5Bz5/rS1ulkt1tSr3mhLyxxwgCin4WRFErPGM=";                                                                                                                                                                                                                                    
          };                                                                                                                                                                                                                                                                                                 
        in rec                                                                                                                                                                                                                                                                                               
        {                                                                                                                                                                                                                                                                                                    
          capnpc-go = pkgs.buildGoModule {                                                                                                                                                                                                                                                                   
            name = "capnpc-go";                                                                                                                                                                                                                                                                              
            pname = "capnpc-go";                                                                                                                                                                                                                                                                             
            src = go-capnp;                                                                                                                                                                                                                                                                                  
            sourceRoot = "go-capnp";                                                                                                                                                                                                                                                                         
            vendorSha256 = "sha256-DRNbv+jhIHzoBItuiQykrp/pD/46uysFbazLJ59qbqY=";                                                                                                                                                                                                                            
            buildPhase = ''                                                                                                                                                                                                                                                                                  
              go install ./capnpc-go                                                                                                                                                                                                                                                                         
            '';                                                                                                                                                                                                                                                                                              
          };                                                                                                                                                                                                                                                                                                 
          rocket_crash = pkgs.stdenv.mkDerivation {                                                                                                                                                                                                                                                          
            name = "rocket_crash";                                                                                                                                                                                                                                                                           
            pname = "rocket_crash";                                                                                                                                                                                                                                                                          
            version = builtins.substring 0 8 (self.lastModifiedDate or "19700101");                                                                                                                                                                                                                          
            srcs = [                                                                                                                                                                                                                                                                                         
              go-capnp                                                                                                                                                                                                                                                                                       
            ];                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                             
            GOMAXPROCS = "1";                                                                                                                                                                                                                                                                                
                                                                                                                                                                                                                                                                                                             
            sourceRoot = "rocket_crash-src/";                                                                                                                                                                                                                                                                
            preConfigure = ''                                                                                                                                                                                                                                                                                
              export XDG_CACHE_HOME=$TMPDIR/.cache                                                                                                                                                                                                                                                           
              export GOPATH=$XDG_CACHE_HOME/go                                                                                                                                                                                                                                                               
            '';                                                                                                                                                                                                                                                                                              
            shellHook = ''                                                                                                                                                                                                                                                                                   
              echo "called shellhook for dev"                                                                                                                                                                                                                                                                
              export CAPNPC_GO_STD="${capnpc-go}"                                                                                                                                                                                                                                                            
              echo "${capnpc-go}"                                                                                                                                                                                                                                                                            
            '';                                                                                                                                                                                                                                                                                              
            configureFlags = [                                                                                                                                                                                                                                                                               
              "--with-go-capnp=../go-capnp"                                                                                                                                                                                                                                                                  
            ];                                                                                                                                                                                                                                                                                               
                                                                                                                                                                                                                                                                                                             
            nativeBuildInputs = with pkgs; [                                                                                                                                                                                                                                                                 
              go                                                                                                                                                                                                                                                                                             
              gotools                                                                                                                                                                                                                                                                                        
              capnproto                                                                                                                                                                                                                                                                                      
              capnpc-go                                                                                                                                                                                                                                                                                      
              templ.packages.${system}.templ                                                                                                                                                                                                                                                                 
            ];                                                                                                                                                                                                                                                                                               
          };                                                                                                                                                                                                                                                                                                 
        });                                                                                                                                                                                                                                                                                                  
                                                                                                                                                                                                                                                                                                             
      defaultPackage = forAllSystems (system: self.packages.${system}.rocket_crash);                                                                                                                                                                                                                         
    };                                                                                                                                                                                                                                                                                                       
}