Build fails because org.apache.cordova.dialogs can not be loaded

My build config has not change but I am now getting the following build error:

Dependent plugin "cordova-plugin-compat" already installed on ios.
"plugman install --platform ios --project /tmp/gimlet/932628/project --plugin org.apache.cordova.dialogs": Fetching plugin "org.apache.cordova.dialogs" via npm
Failed to fetch plugin org.apache.cordova.dialogs via registry.
Probably this is either a connection problem, or plugin spec is incorrect.
Check your connection and plugin name/version/URL.
Error: Registry returned 404 for GET on https://registry.npmjs.org/org.apache.cordova.dialogs