当我开始时npm run serve被称为错误sh:cross-env: command not found, I tried some methods like npm install cross-env -D npm install cross-env -g`，这不起作用，有人知道原因吗？请告诉我，谢谢！！！完整的日志：
4 verbose run-script [ 'preserve', 'serve', 'postserve' ]
5 info lifecycle test@1.0.0~preserve: test@1.0.0
6 info lifecycle test@1.0.0~serve: test@1.0.0
7 verbose lifecycle test@1.0.0~serve: unsafe-perm in lifecycle true
8 verbose lifecycle test@1.0.0~serve: PATH: /Users/liujunhua/.nvm/versions/node/v14.16.1/lib/node_modules/npm/node_modules/npm-lifecycle/node-gyp-bin:/Users/liujunhua/Code/dh_cli_template/dist/2021-04-23 18:06:15/node_modules/.bin:/Users/liujunhua/.nvm/versions/node/v14.16.1/bin:/usr/local/bin:/usr/bin:/bin:/usr/sbin:/sbin:/Users/liujunhua/Development/flutter/bin:/Library/Apple/usr/bin
9 verbose lifecycle test@1.0.0~serve: CWD: /Users/liujunhua/Code/dh_cli_template/dist/2021-04-23 18:06:15
10 silly lifecycle test@1.0.0~serve: Args: [
10 silly lifecycle '-c',
10 silly lifecycle 'cross-env NODE_ENV=development webpack-dev-server --mode=development --config webpack.config.js --colors'
10 silly lifecycle ]
11 info lifecycle test@1.0.0~serve: Failed to exec serve script
12 verbose stack Error: test@1.0.0 serve: `cross-env NODE_ENV=development webpack-dev-server --mode=development --config webpack.config.js --colors`
12 verbose stack spawn ENOENT
12 verbose stack at ChildProcess.<anonymous> (/Users/liujunhua/.nvm/versions/node/v14.16.1/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:48:18)
12 verbose stack at ChildProcess.emit (events.js:315:20)
12 verbose stack at maybeClose (internal/child_process.js:1048:16)
12 verbose stack at Process.ChildProcess._handle.onexit (internal/child_process.js:288:5)
13 verbose pkgid test@1.0.0
14 verbose cwd /Users/liujunhua/Code/dh_cli_template/dist/2021-04-23 18:06:15
15 verbose Darwin 19.6.0
16 verbose argv "/Users/liujunhua/.nvm/versions/node/v14.16.1/bin/node" "/Users/liujunhua/.nvm/versions/node/v14.16.1/bin/npm" "run" "serve"
17 verbose node v14.16.1
18 verbose npm v6.14.12
19 error code ELIFECYCLE
20 error syscall spawn
21 error file sh
22 error errno ENOENT
23 error test@1.0.0 serve: `cross-env NODE_ENV=development webpack-dev-server --mode=development --config webpack.config.js --colors`
23 error spawn ENOENT
24 error Failed at the test@1.0.0 serve script.
24 error This is probably not a problem with npm. There is likely additional logging output above.
25 verbose exit [ 1, true ]