I found three small inconsistencies in utf8-chicken-test.scm while
working on some other things. I added a commit with a fix to my earlier
pull request on GitHub.  Here is the summary:

  Fix substring, string-replicate calls in utf8-chicken-test.scm.

  An invocation of substring, and two of string-replicate, were short
  one argument.  The modified utf8-chicken-test.scm is now consistent
  with chicken-test.scm in this regard.

  e7e0ede

Regards,

-chaw