gatsby-starter-gcn: npm test failure on check-pretty script

When running npm test with a new install of the repo, I’m getting:

npm ERR! gatsby-starter-gcn@1.1.0 check-pretty: prettier -l {,src/**/}*.{js,jsx,json,css,scss} npm ERR! Exit status 2 npm ERR! npm ERR! Failed at the gatsby-starter-gcn@1.1.0 check-pretty script.

I’m looking into whether this might be an environmental issue (running node on Windows 10).