I rewrote srfi/srfi-64.scm file using cond-expand but don't know it works.
On Guile 2.0, it works;
  $ guile -L `pwd` --use-srfi=64 srfi-64-test.scm
  %%%% Starting test SRFI 64 - Meta-Test Suite  (Writing full log to "SRFI 64 - Meta-Test Suite.log")
  # of expected passes      51
  # of expected failures    2

2012/4/14 Per Bothner <per@bothner.com>
This is nice.  It would be great if the Guile port would be merged
into the reference implementation, presumably using cond-expand.
That way bug-fixes or changes in one could be more easily be
merged into the other.
 
I have no idea how to use your testing.scm file on Kawa or Chicken.
Without testing.scm file, srfi-64-test.scm can be checked on Kawa;
  $ kawa srfi-64-test.scm 
  %%%% Starting test SRFI 64 - Meta-Test Suite  (Writing full log to "SRFI 64 - Meta-Test Suite.log")
  # of expected passes      51
  # of expected failures    2
I don't know how to use testing.scm and my srfi/srfi-64.scm on Kawa.