TypeError: UTIL.error is not a function

[neongreen]

$ npm i -g html-differ@1.4.0
$ html-differ --help

/usr/local/lib/node_modules/html-differ/node_modules/coa/lib/cmd.js:243
        UTIL.error(msg);
             ^

TypeError: UTIL.error is not a function
    at process.<anonymous> (/usr/local/lib/node_modules/html-differ/node_modules/coa/lib/cmd.js:243:14)
    at Object.onceWrapper (events.js:284:20)
    at process.emit (events.js:196:13)

$ npm --version
6.9.0
$ node --version
v12.1.0