Error when npm run pub

pm notice total files:   37                                      
npm notice 
+ rc-select@8.8.1
published
/Users/afc163/Projects/select/node_modules/_async-done@1.3.1@async-done/index.js:18
    throw err;
    ^

Error [ERR_UNHANDLED_ERROR]: Unhandled error. ([object Object])
    at Gulp.emit (events.js:171:17)
    at Gulp.EventEmitter.emit (domain.js:442:20)
    at Object.error (/Users/afc163/Projects/select/node_modules/_undertaker@1.2.0@undertaker/lib/helpers/createExtensions.js:61:10)
    at handler (/Users/afc163/Projects/select/node_modules/_now-and-later@2.0.0@now-and-later/lib/mapSeries.js:43:14)
    at f (/Users/afc163/Projects/select/node_modules/_once@1.4.0@once/once.js:25:25)
    at f (/Users/afc163/Projects/select/node_modules/_once@1.4.0@once/once.js:25:25)
    at tryCatch (/Users/afc163/Projects/select/node_modules/_async-done@1.3.1@async-done/index.js:24:15)
    at done (/Users/afc163/Projects/select/node_modules/_async-done@1.3.1@async-done/index.js:40:12)
    at Domain.onError (/Users/afc163/Projects/select/node_modules/_async-done@1.3.1@async-done/index.js:51:5)
    at Object.onceWrapper (events.js:273:13)
    at Domain.emit (events.js:182:13)
    at Domain.EventEmitter.emit (domain.js:442:20)
    at Domain._errorHandler (domain.js:224:23)
    at Object.setUncaughtExceptionCaptureCallback (domain.js:140:29)
    at process._fatalException (internal/bootstrap/node.js:490:31)

Start by reproducing npm run pub and inspect the failure after rc-select@8.8.1 is published. Trace the error through node_modules/_async-done@1.3.1@async-done/index.js and the related undertaker and now-and-later stack frames. Done means the publish command completes without the unhandled error.