TypeError: Object -3 has no method 'bind'

[maxlinc]

I've been getting this error inside cleanurls. I have no idea why. The key with a value of 3 is _curOpen.

error: Something went wrong with the action
error: An error occured:
TypeError: Object -3 has no method 'bind'
    at Object.<anonymous> (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad-plugin-cleanurls/node_modules/safefs/out/lib/safefs.js:119:27)
    at Object.<anonymous> (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad-plugin-cleanurls/node_modules/safefs/out/lib/safefs.js:125:4)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad-plugin-eco/node_modules/eco/node_modules/coffee-script/lib/coffee-script/coffee-script.js:211:36)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at CleanUrlsPlugin.writeAfter (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad-plugin-cleanurls/out/cleanurls.plugin.js:66:18)
    at ambi (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad/node_modules/ambi/out/lib/ambi.js:23:18)
    at Task.<anonymous> (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad/node_modules/event-emitter-grouped/out/lib/event-emitter-grouped.js:38:23)
    at ambi (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad/node_modules/ambi/out/lib/ambi.js:23:18)
    at fire (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad/node_modules/taskgroup/out/lib/taskgroup.js:159:23)
    at b (domain.js:183:18)
    at Domain.run (domain.js:123:23)
    at Task.fire (/Users/Thoughtworker/repos/opensource/zurb-foundation.docpad/node_modules/docpad/node_modules/taskgroup/out/lib/taskgroup.js:166:25)
    at processImmediate [as _immediateCallback] (timers.js:330:15)

[maxlinc]

Line numbers are off by one... I inserted a log statement to get the key/value pair.