我尝试运行npm run dev，但出现以下错误：

sh: 1: cross-env: Permission denied
npm ERR! code ELIFECYCLE
npm ERR! errno 126
npm ERR! @ development: `cross-env NODE_ENV=development node_modules/webpack/bin/webpack.js --progress --hide-modules --config=node_modules/laravel-mix/setup/webpack.config.js`
npm ERR! Exit status 126
npm ERR! 
npm ERR! Failed at the @ development script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/shanmaseen/.npm/_logs/2019-02-22T16_32_08_191Z-debug.log
npm ERR! code ELIFECYCLE
npm ERR! errno 126
npm ERR! @ dev: `npm run development`
npm ERR! Exit status 126
npm ERR! 
npm ERR! Failed at the @ dev script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

npm ERR! A complete log of this run can be found in:
npm ERR!     /home/shanmaseen/.npm/_logs/2019-02-22T16_32_08_241Z-debug.log

我已经在网上搜索了一个星期了，一点帮助都没有！
我甚至尝试从package.json脚本中删除'cross-env'，但随后webpack：发生权限被拒绝的情况，表明权限错误不是由跨环境本身引起的。
这是错误日志：

0 info it worked if it ends with ok
1 verbose cli [ '/usr/bin/node', '/usr/bin/npm', 'run', 'dev' ]
2 info using npm@6.7.0
3 info using node@v11.10.0
4 verbose run-script [ 'predev', 'dev', 'postdev' ]
5 info lifecycle @~predev: @
6 info lifecycle @~dev: @
7 verbose lifecycle @~dev: unsafe-perm in lifecycle true
8 verbose lifecycle @~dev: PATH: /usr/lib/node_modules/npm/node_modules/npm-lifecycle/node-gyp-bin:/media/e/www/mwar/node_modules/.bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:/snap/bin
9 verbose lifecycle @~dev: CWD: /media/e/www/mwar
10 silly lifecycle @~dev: Args: [ '-c', 'npm run development' ]
11 silly lifecycle @~dev: Returned: code: 126  signal: null
12 info lifecycle @~dev: Failed to exec dev script
13 verbose stack Error: @ dev: `npm run development`
13 verbose stack Exit status 126
13 verbose stack     at EventEmitter.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/index.js:301:16)
13 verbose stack     at EventEmitter.emit (events.js:197:13)
13 verbose stack     at ChildProcess.<anonymous> (/usr/lib/node_modules/npm/node_modules/npm-lifecycle/lib/spawn.js:55:14)
13 verbose stack     at ChildProcess.emit (events.js:197:13)
13 verbose stack     at maybeClose (internal/child_process.js:984:16)
13 verbose stack     at Process.ChildProcess._handle.onexit (internal/child_process.js:265:5)
14 verbose pkgid @
15 verbose cwd /media/e/www/mwar
16 verbose Linux 4.18.0-15-generic
17 verbose argv "/usr/bin/node" "/usr/bin/npm" "run" "dev"
18 verbose node v11.10.0
19 verbose npm  v6.7.0
20 error code ELIFECYCLE
21 error errno 126
22 error @ dev: `npm run development`
22 error Exit status 126
23 error Failed at the @ dev script.
23 error This is probably not a problem with npm. There is likely additional logging output above.
24 verbose exit [ 126, true ]

我用的是拉瑞威5.7mix。
节点版本：v11.10.0 npm版本：6.7.0
有什么需要帮忙的吗？