try fix script

flake.nix

@@ -5,8 +5,7 @@
 
   outputs = _: {
     lib = {
-      mkLib = pkgs: pwd: import ./lib.nix { inherit pkgs pwd; };
+      mkLib = pkgs: import ./lib.nix { inherit pkgs; };
     };
   };
 }
-

lib.nix

@@ -1,7 +1,7 @@
 { pkgs, pwd }:
 let
   inherit (pkgs) lib;
-  runtime = builtins.toString pwd + "/.compose";
+  runtime = ".compose";
 in
 {
   mkWrapper =
@@ -122,7 +122,7 @@ in
           echo "PostgreSQL initdb process completed"
           echo
         fi
-        cp ${configFile} ${data_dir}/postgresql.conf
+        cp ${configFile} $PGDATA/postgresql.conf
         if [[ "$POSTGRES_RUN_INITIAL_SCRIPT" == "true" ]]; then
           echo
           echo "PostgreSQL is setting up the initial database"
@@ -142,7 +142,7 @@ in
         name = "run-postgres";
         text = ''
           set -euo pipefail
-          export PGDATA=${data_dir} PGHOST=${runtimeDir} PGPORT=${builtins.toString port}
+          export PGDATA=$(realpath ${data_dir}) PGHOST=$(realpath (${runtimeDir}) PGPORT=${builtins.toString port}
           mkdir -p ${lib.escapeShellArg runtimeDir}
           ${setupScript}/bin/setup-postgres
           ${package}/bin/postgres