diff --git a/src/mtran/README.md b/src/mtran/README.md
index 67716ad..7eed681 100644
--- a/src/mtran/README.md
+++ b/src/mtran/README.md
@@ -48,10 +48,12 @@ cd ~/smart-healthcare-2026/src/mtran
 
 ## 3. 准备依赖、sidecar 和模型
 
-从 `smart-healthcare-2026/src/mtran` 执行：
+先加载日常终端环境，再执行：
 
 ```bash
-./dependencies/auto_install.sh
+source ~/.bashrc
+cd ~/smart-healthcare-2026/src/mtran/dependencies
+./auto_install.sh
 ```
 
 脚本会请求 `sudo` 安装非 ROS apt 包，在 `dependencies/tools` 安装固定版本 Bun，
@@ -66,9 +68,10 @@ Then: source install/setup.bash && ros2 launch mtran translator.launch.py
 
 ## 4. 检查准备结果
 
-仍从 `smart-healthcare-2026/src/mtran` 执行：
+返回 `smart-healthcare-2026/src/mtran` 执行：
 
 ```bash
+cd ..
 file runtime/bin/mtranserver
 test -s runtime/config/records.json
 ls -lh models/en_zh-Hans
@@ -96,7 +99,7 @@ models/en_zh-Hans/trgvocab.enzh.spm
 从工作区根目录 `smart-healthcare-2026` 执行，而不是从包目录执行：
 
 ```bash
-source /opt/ros/humble/setup.bash
+source ~/.bashrc
 PYTHONNOUSERSITE=1 colcon build --packages-select mtran
 ```
 
@@ -115,7 +118,7 @@ CMake 不会联网、安装依赖或调用 Bun。它只检查第 4 节的准备
 从 `smart-healthcare-2026` 执行：
 
 ```bash
-source /opt/ros/humble/setup.bash
+source ~/.bashrc
 source install/setup.bash
 PYTHONNOUSERSITE=1 ros2 launch mtran translator.launch.py
 ```
@@ -132,7 +135,7 @@ MTranServer is healthy and the en-to-zh-Hans model is warm
 保留启动终端，在第二个终端中从 `smart-healthcare-2026` 执行：
 
 ```bash
-source /opt/ros/humble/setup.bash
+source ~/.bashrc
 source install/setup.bash
 ros2 service call /translate_en_to_zh \
   mtran/srv/TranslateEnglishToChinese \
@@ -215,20 +218,20 @@ C++ 源码和模型数据不区分 CPU 架构。`auto_install.sh` 在运行机
 - 架构正确的 sidecar
 - 哈希和大小正确的四个模型文件
 
-只重新构建 sidecar，从 `smart-healthcare-2026/src/mtran` 执行：
+只重新构建 sidecar，从 `smart-healthcare-2026/src/mtran/dependencies` 执行：
 
 ```bash
-rm -f runtime/bin/mtranserver
-rm -rf .build/mtranserver
-./dependencies/auto_install.sh
+rm -f ../runtime/bin/mtranserver
+rm -rf ../.build/mtranserver
+./auto_install.sh
 ```
 
 完全重新准备，从同一目录执行：
 
 ```bash
-rm -rf dependencies/tools .build runtime/config models/en_zh-Hans
-rm -f runtime/bin/mtranserver
-./dependencies/auto_install.sh
+rm -rf tools ../.build ../runtime/config ../models/en_zh-Hans
+rm -f ../runtime/bin/mtranserver
+./auto_install.sh
 ```
 
 清理 ROS2 构建结果，从 `smart-healthcare-2026` 执行：
diff --git a/src/mtran/dependencies/auto_install.sh b/src/mtran/dependencies/auto_install.sh
index bc52b12..6ad2b29 100755
--- a/src/mtran/dependencies/auto_install.sh
+++ b/src/mtran/dependencies/auto_install.sh
@@ -17,7 +17,6 @@ bun_bin=""
 BUN_VERSION=1.3.14
 os_release_file=${MTRAN_OS_RELEASE_FILE:-/etc/os-release}
 machine=${MTRAN_MACHINE:-$(uname -m)}
-ros_prefix=${MTRAN_ROS_PREFIX:-/opt/ros/humble}
 
 die()
 {
@@ -38,9 +37,8 @@ validate_host()
     *) die "supported CPU architecture must be x86_64 or aarch64; found ${machine}." ;;
   esac
 
-  if [[ "${ROS_DISTRO:-}" != "humble" && ! -d "${ros_prefix}" ]]; then
-    die "ROS2 Humble must already be installed by the user."
-  fi
+  [[ "${ROS_DISTRO:-}" == "humble" ]] || \
+    die "ROS2 Humble environment must be sourced before running this script."
 
   [[ -f "${vendor_source}/package.json" && -f "${vendor_source}/bun.lock" ]] || \
     die "vendored MTranServer source is missing under vendor/mtranserver."
diff --git a/src/mtran/dependencies/dependencies.txt b/src/mtran/dependencies/dependencies.txt
index a4d3d7d..aeb7a5c 100644
--- a/src/mtran/dependencies/dependencies.txt
+++ b/src/mtran/dependencies/dependencies.txt
@@ -7,6 +7,8 @@ User-provided prerequisites
 ---------------------------
 - Ubuntu 22.04 on x86_64 or aarch64.
 - ROS2 Humble, installed and maintained by the user.
+- The ROS2 Humble environment must be sourced before running auto_install.sh
+  or the package shell tests.
 - Python 3 from Ubuntu/ROS2, used for runtime-data integrity checks.
 - Required ROS packages:
   - ament_cmake
diff --git a/src/mtran/test/test_auto_install.sh b/src/mtran/test/test_auto_install.sh
index ac11c47..528af25 100644
--- a/src/mtran/test/test_auto_install.sh
+++ b/src/mtran/test/test_auto_install.sh
@@ -149,7 +149,6 @@ expect_failure "x86_64 or aarch64" env \
 expect_failure "ROS2 Humble" env -u ROS_DISTRO \
   MTRAN_OS_RELEASE_FILE="${ubuntu_release}" \
   MTRAN_MACHINE=x86_64 \
-  MTRAN_ROS_PREFIX="${tmp_root}/missing-ros" \
   bash "${installer}"
 
 missing_vendor="${tmp_root}/missing-vendor"
diff --git a/src/mtran/test/test_cmake_preparation.sh b/src/mtran/test/test_cmake_preparation.sh
index 2054d09..7c2abf4 100644
--- a/src/mtran/test/test_cmake_preparation.sh
+++ b/src/mtran/test/test_cmake_preparation.sh
@@ -17,10 +17,10 @@ rsync -a \
   --exclude 'models/en_zh-Hans/' \
   "${root}/" "${fixture}/"
 
-# shellcheck disable=SC1091
-set +u
-source /opt/ros/humble/setup.bash
-set -u
+if [[ "${ROS_DISTRO:-}" != "humble" ]]; then
+  echo "ROS2 Humble environment must be sourced before running this test" >&2
+  exit 1
+fi
 
 if missing_output=$(cmake -S "${fixture}" -B "${fixture}/build-missing" 2>&1); then
   echo "CMake unexpectedly configured without prepared runtime files" >&2
diff --git a/src/mtran/test/test_readme_commands.sh b/src/mtran/test/test_readme_commands.sh
index b5d9f4b..c7a89f3 100644
--- a/src/mtran/test/test_readme_commands.sh
+++ b/src/mtran/test/test_readme_commands.sh
@@ -6,7 +6,9 @@ readme="${root}/README.md"
 
 required_entries=(
   "smart-healthcare-2026/src/mtran"
-  "./dependencies/auto_install.sh"
+  "src/mtran/dependencies"
+  "./auto_install.sh"
+  "source ~/.bashrc"
   "colcon build --packages-select mtran"
   "ros2 launch mtran translator.launch.py"
   "mtran/srv/TranslateEnglishToChinese"
@@ -23,7 +25,7 @@ for required in "${required_entries[@]}"; do
   grep -Fq "${required}" "${readme}"
 done
 
-if rg -n 'mtran_ros2|/home/hikos/MTranServer|Path\.cwd|build_mtranserver\.sh' "${readme}"; then
+if rg -n 'mtran_ros2|MTranServer/migrate_ws|Path\.cwd|build_mtranserver\.sh' "${readme}"; then
   echo "README still contains an obsolete package name or local path" >&2
   exit 1
 fi
diff --git a/src/mtran/test/test_shell_paths.py b/src/mtran/test/test_shell_paths.py
new file mode 100644
index 0000000..fbf44ed
--- /dev/null
+++ b/src/mtran/test/test_shell_paths.py
@@ -0,0 +1,12 @@
+from pathlib import Path
+
+
+root = Path(__file__).resolve().parents[1]
+installer = (root / "dependencies" / "auto_install.sh").read_text(encoding="utf-8")
+cmake_test = (root / "test" / "test_cmake_preparation.sh").read_text(encoding="utf-8")
+
+assert "pwd -P" in installer
+assert "/opt/ros/humble" not in installer
+assert "MTRAN_ROS_PREFIX" not in installer
+assert "/opt/ros/humble" not in cmake_test
+assert "ROS_DISTRO" in cmake_test