Sass не работает, когда я использую фундамент 6 для электронной почты

Question

Когда я использовал zurb-foundation-6 для шаблона электронной почты, я обнаружил, что команда npm run build не выполняется из-за

[02:42:06] Failed to load external module @babel/register
[02:42:06] Requiring external module babel-register
[02:42:08] Using gulpfile ~/IdeaProjects/edm/gulpfile.babel.js
[02:42:08] Starting 'default'...
[02:42:08] Starting 'build'...
[02:42:08] Starting 'clean'...
[02:42:08] Finished 'clean' after 5.29 ms
[02:42:08] Starting 'pages'...
[02:42:09] Finished 'pages' after 380 ms
[02:42:09] Starting 'sass'...
[02:42:09] 'sass' errored after 339 ms
[02:42:09] TypeError in plugin 'gulp-uncss'
Message:
    "file" argument must be a non-empty string
Details:
    domainEmitter: [object Object]
    domain: [object Object]
    domainThrown: false
[02:42:09] 'build' errored after 726 ms
[02:42:09] 'default' errored after 728 ms
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! foundation-emails-template@1.0.0 build: `gulp --production`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the foundation-emails-template@1.0.0 build 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!     /Users/baixu/.npm/_logs/2018-05-14T18_42_09_404Z-debug.log