build: make environment adapt to Nixos

devenv.nix

@@ -60,6 +60,18 @@
     KERNEL_DIR = "${pkgs.linuxHeaders}/include";
   };
 
+  # 创建 .venv 软链接到 .devenv/state/venv
+  scripts.linkVenv.exec = ''
+    if [ -L ".venv" ] || [ ! -e ".venv" ]; then
+        rm -f ".venv" 2>/dev/null || true
+        ln -s ".devenv/state/venv" ".venv"
+        echo "Created symlink: .venv -> .devenv/state/venv"
+    elif [ -e ".venv" ]; then
+        echo "Warning: .venv exists and is not a symlink. Not replacing it."
+        echo "If you want to replace it with a symlink, please remove it manually first."
+    fi
+  '';
+
   # https://devenv.sh/basics/
   enterShell = ''
     export NIX_LD_LIBRARY_PATH="$NIX_LD_LIBRARY_PATH:${lib.makeLibraryPath [ pkgs.linuxHeaders ]}";
@@ -69,5 +81,7 @@
     echo "LD_LIBRARY_PATH set to $LD_LIBRARY_PATH"
     echo "CPATH set to $CPATH"
     echo "KERNEL_DIR set to $KERNEL_DIR"
+
+    linkVenv
   '';
 }