coleslaw:main stops working when title is in Thai

In my pali.post

;;;;;
title: บาลีอักษรไทย
tags: 
date: 2014-06-03
format: md
excerpt: 
;;;;;

...

After I ran (coleslaw:main "/my/folder")

I got this error messages:

debugger invoked on a SB-INT:C-STRING-ENCODING-ERROR in thread
#<THREAD "main thread" RUNNING {10005585B3}>:
  NIL c-string encoding error: the character with code 3610 cannot be encoded.

Type HELP for debugger help, or (SB-EXT:EXIT) to exit from SBCL.

restarts (invokable by number or by possibly-abbreviated name):
  0: [ABORT] Exit debugger, returning to top level.

(SB-IMPL::%EXTERNAL-FORMAT-ENCODING-ERROR NIL 3610)
0]

If I change title: บาลีอักษรไทย to title: Pali, it works.

coleslaw-org / coleslaw

coleslaw:main stops working when title is in Thai #158