Getting SIGSEGV with ember-cli-sass

Installing this on Ember CLI 1.13.13, via ember install ember-cli-sass.

package.json now has "ember-cli-sass": "^5.2.1". When I execute ember server, I get:

'ember server' terminated by signal SIGSEGV (Address boundary error)

Removing "ember-cli-sass": "^5.2.1" from package.json starts ember server fine.

Any reason why this is happening?